# Ravelli RV80 - Problem: Air Flow Meter



## BrianJ (Dec 30, 2015)

So I moved into a place in the middle of November that is heated by a free standing pellet stove - a Ravelli brand model RV80. Let me start by saying the stove had some issues when I moved in. The previous tenant (who I am still in contact with) said she enjoyed several years of excellent service from the pellet stove, but that recently it had begun operating strangely.

She told me that she had been unable to elevate the heat level from 1 to any of the other settings, either by the remote control or through the control panel atop the stove (both had worked before). Furthermore, all efforts to contact the manufacturer or the retailer yielded no fruit. Now, this isn't a big deal for me, I don't mind it running on the lowest setting or taking a little while to heat up the place. It heats the place fine and I'm happy.

Or I was.

A couple days ago the pellet stove started beeping at me periodically and displaying a new error message:

09 - Air Flow Meter

Now I am straight bumpuzzled as to what this could mean. The manual I looked through had a list of error messages and (after doing some translating from Italian to English) I found that two of the errors listed referred to a broken or a dirty air intake sensor... or at least I think? It's difficult to research because it's a foreign product and what little there exists in English isn't all that helpful.

I've cleaned it, both the stove and the air intake sensor, then disabled the air intake sensor by unplugging it from the circuit board (everything is still in place and in tact though). The stove still displays this error and will beep every 20 minutes or so about it. Meanwhile it still heats the place fine and appears to be working as well as it ever did. What's the deal here? Am I fiddling with the wrong part? Is there a different air flow meter? I theorized that the exhaust might be clogged somewhere and in need of cleaning but I'm not sure how to get the chimney apart to do that and before I started something so big I thought I would come and check here.

Any ideas? Suggestions? Anything I can try?

Thanks so much,
-Brian


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## Lake Girl (Dec 30, 2015)

Are they referring to the vacuum switch?

Edit:  Referring to the debimeter but not sure of it's location and does not appear to be on my stove...

This manual might be of help:


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## Lake Girl (Dec 30, 2015)

Please be very cautious on messing with factory settings ... may make matters worse  If you can find location of debimeter, cleaning may be the answer...  or replacement.

Edit:  page 21 of the manual
Your stove is forced into power level 1 due to failed communication from flow meter - either meter is no longer functioning or connections are a problem.

There appears to be two dealers in your area of Oregon http://usa.ravelligroup.it/punti_vendita_usa

Welcome to the forum and keep us posted.


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## Pelleting In NJ (Dec 31, 2015)

Yes, your stove has one airflow sensor, also called the "Debimeter" in the Technical Manual.  If you cleaned it, and it still does not work when reinstalled (also check the connector that goes to the control board), it sounds like you need a new airflow sensor. Check Ebay, or see if Barry, at North Forge Heating (Annville PA, (717) 867 1744) ) can get you one.

Ravelli part number 0634654074997

http://www.ebay.fr/itm/RAVELLI-Debimetre-support-Systeme-RDS-/311279318012http://www.ebay.com/itm/191624319814


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## Pelleting In NJ (Dec 31, 2015)

http://www.ebay.com/itm/191624319814


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## BrianJ (Jan 1, 2016)

Super helpful remarks you guys, thank you so much. I will look into what you have brought to light and let you guys now if anything (or nothing) comes of it.


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## Don2222 (Jan 2, 2016)

I had a stove with the same problem. The vacuum switch hose was clogged where it attached to the vacuum switch. After cleaning it the error was gone. After a while the error came back so by replacing the vacuum switch it fixed the problem.
Just my 2 cents


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## johnnyboy61 (Nov 10, 2017)

BrianJ said:


> So I moved into a place in the middle of November that is heated by a free standing pellet stove - a Ravelli brand model RV80. Let me start by saying the stove had some issues when I moved in. The previous tenant (who I am still in contact with) said she enjoyed several years of excellent service from the pellet stove, but that recently it had begun operating strangely.
> 
> She told me that she had been unable to elevate the heat level from 1 to any of the other settings, either by the remote control or through the control panel atop the stove (both had worked before). Furthermore, all efforts to contact the manufacturer or the retailer yielded no fruit. Now, this isn't a big deal for me, I don't mind it running on the lowest setting or taking a little while to heat up the place. It heats the place fine and I'm happy.
> 
> ...


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## johnnyboy61 (Nov 10, 2017)

where was the flow meter located? I don't see it on manual


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## rich2500 (Nov 10, 2017)

It's in the fresh air intake tube, if you remove the fresh air vent from the back of the stove and look in you will see it.


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## Monica in France (Nov 11, 2017)

I have actually purchased an airflow meter for a Ravelli RDS system : I was dreaming about converting my Monica to a more sophisticated algorithm using an Arduino to replace the actual micro-computer,  and consider this sensor fundamental for better control ( especially when it is getting near a 'clean needed ' situation).
Despite its high price , this 'airflow meter' was entirely  passive: composed of two temperature sensors ( needing bridges) and a heating element. The circuitry necessary to be able to use it is apparently on the printed circuit board.   When I put this project back 'in plan' I will look at the car fuel injection market instead.
So while it is possible that this component is 'hors service' I think it unlikely. It is however easy to remove and check that it has continuity. If it is duff , it is probably  the heating resistor which , by chance , is the easiest to check.


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## waltonb (Nov 12, 2017)

My Ravelli RV-80 has this exact problem.   Display "09- Air flow meter" followed by 10 beeps.  Stove will operate only in "Modulate" mode, which means no high RPM fan to blow the hot air around.   Looking for some solution.

There seems to be no online source in the US for the "debimeter" (air flow sensor) which is located in the air intake pipe just inside the rear panel.

Cleaning does not make a difference... in fact it does not look the least bit dirty.

Is there any hope that I can fix this?


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## rich2500 (Nov 12, 2017)

if you call either of these places they should be able to get you a new flow meter
http://northforgeheating.com/
http://www.woodmanspartsplus.com/catalog.aspx
https://kingdombiofuel.com/


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## johnnyboy61 (Nov 13, 2017)

rich2500 said:


> if you call either of these places they should be able to get you a new flow meter
> http://northforgeheating.com/
> http://www.woodmanspartsplus.com/catalog.aspx
> https://kingdombiofuel.com/


Thank you. I'm trying to get a picture of it and unable to find one


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## johnnyboy61 (Nov 13, 2017)

Thanks. Trying to get a picture of flow meter but unable to find one


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## Ssyko (Nov 13, 2017)




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## johnnyboy61 (Nov 13, 2017)

Ssyko said:


> View attachment 215790





Ssyko said:


> View attachment 215790


Great thanks. W


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## johnnyboy61 (Nov 13, 2017)

Thank you. Wanted to make sure I had the right piece. I did. Now just have to find one


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## johnnyboy61 (Nov 14, 2017)

Ssyko said:


> View attachment 215790


Thank you


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## Ssyko (Nov 14, 2017)

Google is your friend


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## Joe into Physics (Nov 21, 2017)

I removed the outside air supply hose and looked into the air intake of my stove and immediately spotted the two green "fingers" pictured in the message above from Ssyko.  I lifted out the two panels to open up the right side of the stove (as you face its front), and  there, about 8 inches in from the end of the intake pipe was the red rubber sensor body with a 4-wire electrical connector plugged into it.  It was held on by two screws and three disposable tie wraps, which hold the rubber down tightly to seal the opening in the pipe.  I removed the sensor and examined it, including under a low power microscope, whose magnification was necessary to read "75R0" on the heater resistor, indicating 75.0 ohms.  My measurement of it came within 1% of spec.  Those two green "fingers" in Ssyko's photo are indeed extensions of a circuit board reaching across the air passage.  The upstream finger has a chip thermistor "RT2" which read about 11,700 ohms at 72 Fahrenheit (22 C).  The downstream finger has the 75 ohm heater resistor right next to another thermistor, "RT1" which read about 13,000 ohms at the same temperature, or 11% higher than "RT2."  These are probably nominally the same component, and unlike ordinary resistors, these thermistor components typically are spec'd to within 10% on either side of nominal at a reference temperature, meaning that the 11% ratio difference could be within spec.  I haven't checked what voltage goes to the heater resistor when in the stove circuit.  Logic circuits typically operate with a supply somewhere between 3 and 5 volts, with 3.3 being typical.  Having a 5 volt supply handy, I used that for a test, which should cause 0.33 watts of heating in 75 ohms.  That amount of heat, applied in still air, lowered the thermistor resistance from 11,700 ohms to 1,500 ohms in the space of 40 seconds and, with the resistance close to leveled-off, I blew a hair dryer on cool across the sensor, cooling it and raising the resistance back up to 5600 ohms.  Thermistors of this type respond exponentially to temperature change, and the extreme resistance changes observed here seem totally normal in this setting.  The motherboard circuit probably senses a ratio of resistances and triggers an "insufficient air flow" signal when that ratio crosses a specific threshold.  Blowing air on the sensor caused a 3.7-to-1 ratio change in resistance, while operation on a 3.3v rather than 5.0v supply might drop that ratio down from 3.7 to 2.4 (assuming an exponential temperature response).  That ratio range, compared to a measured 11% resistor mismatch at matching temperatures, leads me to doubt that the resistor mismatch could account for an error reading.  Also, after having the stove work fine for its first year, and with no obvious sign of malfunction in the sensor, why should I think that a thermistor being out-of-spec would suddenly cause a problem?  I'll report back as I learn more, but it seems to me that the sensor malfunction error message isn't there because the sensor itself is defective.  That, of course, represents a "statistical sample of one," so I'd be cautious about generalizing to what normally causes this sensor error problem.  Also, heating a circuit board of this size at 0.33 watts or below, in a cooling forced air stream, should not unduly stress the circuit components, so that I wouldn't expect frequent failures in this extremely simple three-component circuit.


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## Mt Bob (Nov 21, 2017)

Very nicely written.For your information,older car MAF (mass air flow) sensors could throw a fault code from having a film of dirt over them,then manufacturers loosened up the error reporting,but cleaning it became part of rotine maintenance.Perhaps these stoves have an software upgrade?If monica checks this post,the old Austroflamm Integras MAF was a BMW based part.


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## Joe into Physics (Nov 21, 2017)

Thanks, bob bare, for the advice regarding MAF (mass air flow) sensors.  I wasn't even thinking about a film of dirt, and cleaning the sensor is an easy first step.  I realize that sensors like this are "for my own protection" (the flip side of same being "protection of the manufacturer from liability when my house burns down"), but perhaps arrogantly believing that I have the skill to take control of this situation and bias the system just a tad in favor of KEEPING THE DAMN STOVE RUNNING  I shall make an adjustment that for me is more accessible than trying to edit the system software.  I have some high-value but similar negative-TC thermistors that have sat in their drawer for about 40 years, so I don't seem desperately in need of preserving them.  I think I'll try an analog tweak and solder one of them in parallel with that above-spec "RT1" component.  That's probably less unwise that placing a penny behind that annoying fuse that keeps blowing.   (Am I inadvertently revealing my age by referring to screw-in fuses???)


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## Ssyko (Nov 21, 2017)

Joe into Physics said:


> That's probably less unwise that placing a penny behind that annoying fuse that keeps blowing. (Am I inadvertently revealing my age by referring to screw-in fuses???)


  right there with ya.


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## Mt Bob (Nov 21, 2017)

Joe into Physics said:


> Thanks, bob bare, for the advice regarding MAF (mass air flow) sensors.  I wasn't even thinking about a film of dirt, and cleaning the sensor is an easy first step.  I realize that sensors like this are "for my own protection" (the flip side of same being "protection of the manufacturer from liability when my house burns down"), but perhaps arrogantly believing that I have the skill to take control of this situation and bias the system just a tad in favor of KEEPING THE DAMN STOVE RUNNING  I shall make an adjustment that for me is more accessible than trying to edit the system software.  I have some high-value but similar negative-TC thermistors that have sat in their drawer for about 40 years, so I don't seem desperately in need of preserving them.  I think I'll try an analog tweak and solder one of them in parallel with that above-spec "RT1" component.  That's probably less unwise that placing a penny behind that annoying fuse that keeps blowing.   (Am I inadvertently revealing my age by referring to screw-in fuses???)


Actually the MAF has nothing to do with protection,in your stove,my integra,or cars,it is for metering the fuel for a cleaner,more efficient burn.


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## Joe into Physics (Nov 22, 2017)

Thanks, Ssyko, for morale boost, and thanks especially, bob bare, for your voice of experience.  Being "into physics" in my case (and for many) can mean forgetting to think about things like plain ol' dirt.  Had the scientist in me prevailed, I would have attempted separate experiments to separate the variables affecting the problem:
1) Since the nominal-10-KOhm thermistor on my unheated reference side was 11% too high, solder a nominal-100-K thermistor in parallel with the 10K to match the sensors that I presume ought to be matched and were not; and after trying that and (ugh!) removing the corrective 100K component for separately evaluating the following step ...
2)  Clean off the sensor probe, in particular the downstream heated green "tongue" (which looked clean to begin with, but the unaided eye can deceive), so that the air flow would remove heat from the dust-free sensor surface with the original efficiency of the new stove.
The frustrated-with-bad-stove engineer in me dispensed with the scientific controls and did both corrections at once, and I cheerfully report that the flow sensor error warning is gone and -- thank you for your wisdom on this, bob -- the flame looks like it's getting the proper proportion of air: not short like a blowtorch and not lazy orange  tongues reaching high into the combustion chamber.  In the months leading up to the warning beeps and error messages, the flames were getting shorter and more blow-torch-like, a seeming indication that the flow sensor was under-reporting the air flow and the blower control was responding by blowing too much air.  The fact that the problem was progressive would point to cumulative sensor dirt buildup, while a system with properly matched temperature sensors would probably take longer to develop significant problems.

So for others frustrated with this problem, refer to my first entry in this thread, find that red rubber body sensor whose photo Ssyko provided, take it out, clean the two green circuit board probes that normally extend across the middle of the air inlet tube, and put the sensor back like you found it.  For removal, you'll have to cut the plastic tie wraps securing it (if the factory did yours like they did mine), so obviously you'll need new tie wraps to put it back securely.   I cleaned the sensor with a cotton swab dipped in acetone, but 90% isopropyl alcohol (prefer to 70% because the 90% dries better) would probably do just fine.  No guarantees, but if the stove worked when new and then developed this sensor problem, there's a good chance the sensor cleaning will fix it (if I'm not putting too much stock in my statistical sample-of-one  ).

I was unable to find any advice or instructions like this in the Ravelli manual, and I could not identify the flow sensor in the system schematic on the next-to-last page.  To those who service and clean these stoves, I'd guess that pulling out and cleaning the flow sensor should become a regular part of maintenance.  And, Ravelli should get the message.


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## Ssyko (Nov 22, 2017)

Food for thought. I use an ultrasonic cleaner with 90% isopropyl alcohol to clean circuit boards. Works great for some that have been in service for years. This would work also on these “debimeters”


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## Mt Bob (Nov 22, 2017)




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## Ssyko (Nov 22, 2017)

Oh come on Bob, to easy lmao


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## Monica in France (Nov 22, 2017)

Its amusing to note that cleaning was once again the solution to the problem.
and I for one would not have thought that unseen dirt could have caused all this  .
We live and we learn.
But I am perplexed : Joe states that the sensor was over-reporting ; his flame ( or at least his stove's flame) was needing more air. This is the opposite to what I would have expected. This layer of unseen dirt is surely stopping the second heated sensor from being cooled , so the resistor current needed to maintain the small temperature differential between the two sensors would be less and not more . I am expecting it to under-report.
Can someone explain where I'm going wrong ?

Bob Bare :
Did your Integras MAF have its own ( or BMW)  electrics ? From what I understand the support components needed for the Ravelli 'MAF'  make the two thermistors and a resistor look silly.

Happy Thanksgiving.


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## Mt Bob (Nov 22, 2017)

Monica in France said:


> Its amusing to note that cleaning was once again the solution to the problem.
> and I for one would not have thought that unseen dirt could have caused all this  .
> We live and we learn.
> But I am perplexed : Joe states that the sensor was over-reporting ; his flame ( or at least his stove's flame) was needing more air. This is the opposite to what I would have expected. This layer of unseen dirt is surely stopping the second heated sensor from being cooled , so the resistor current needed to maintain the small temperature differential between the two sensors would be less and not more . I am expecting it to under-report.
> ...


Hi nice to talk to you again.I will be honest,I only scanned Joes ramblings(good stuff,just overcomplicated for the normal pellet stove owner),dirt/coating would underreport,same as early car MAF sensors.He may have got it wrong,but the theory is proper.The early integra maf was built(devices and programming) on BMW format,and built by BMW supplier.As BMW was one of the first to use the maf on vehicles,and make it work,makes sense.Maf sensors work by having an ambient air sensor,and a sensor in the airflow,which is provided with a heater,to keep at a constant temperature,the loss of the voltage to keep the sensor at the same temp is what calculates the differences,lots of computer programming.Early car sensors had the ambiant sensor back in the housing,as sensors got better,they put them both in the airstream,I do not know how that works,I am just a mechanic.


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## Joe into Physics (Nov 26, 2017)

To Monica in France and bob bare, I sometimes enjoy writing more than people are inclined to read, but that's OK, that's my style.  In answer to Monica, I was saying "the flow sensor was under-reporting the air flow and the blower control was responding by blowing too much air" ... which was perhaps confusing.  There are actually two ways that the circuitry might work, but either method comes to nearly the same thing:

First Way: A constant voltage is applied to the heater resistor, which puts out a constant wattage.  The temperature sensor next to the resistor measures how much that heated circuit board tongue heats up, and that is compared to the reference temperature of the unheated tongue.  If the heated sensor is dirty, then for the same air flow, the sensor has to get hotter to get the same amount of heat out through the film of dirt and into the air flow, which is AS IF there were less air flow.  So I say that the sensor is under-reporting the air flow, i.e. saying that there is less air flow than there really is.  The blower has to blow harder to compensate and get the sensor to "think" that it's seeing the proper air flow.

Second Way (as described by Monica): The big controller circuit that this little sensor circuit board is plugged into it.  The big circuit adjusts the voltage or current going to the heater resistor in the little sensor circuit, in such a way that there is a constant temperature difference between the reference thermistor and the thermistor next to the heater resistor.  If there is a thin insulating "blanket" of  dirt over the sensor, then less power to the heater is required to maintain the same temperature difference -- it's easier to keep something warm under a blanket.  The big controller circuit then "thinks" that the lower heater power requirement (to maintain the same temperature difference) indicates less air cooling, therefore less air flow, so it responds by making the blower run faster.

I once built a hot wire anemometer using light bulb filaments, which can heat and measure temperature at the same time, since the resistance of the filament increases with increasing temperature caused by heating in the filament whose resistance is  being computed.  I found that the "Second Way" worked better because I could measure very high winds and the extra power to the heated filament would make it more sensitive -- but if the wind went away, doing the sensing the "First Way" caused the filament to glow red hot and burn out in the air, while the "Second Way" reduced the power and kept the filament from overheating.  Also the response was much quicker doing it the "Second Way."  So I thought I had invented a new and improved method, when in fact there are probably many people and manufacturers that do it the "Second Way."


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## Monica in France (Nov 27, 2017)

Thanks Joe , That explains my confusion. Not that your prose was at fault but my reading of it.
My description was based on my memory of the Ravelli installation manual which makes ( made ? ) a big thing of those two thermistors and a resiststor.
But your experience disillusions me somewhat.
My stove has what you could euphemistically describe as first generation  firmware . With the introduction of a third generation technique
like a MAF , I had hoped that Ravelli had developed some serious code.
I would like to hear some ideas on how one could pre-empt your problem long before the <MAF not working> message with a <  MAF needs cleaning > message.
And any ideas on what actually prompted the final message ?
My suggestion would be that on initialization the exhaust fan is run from low to high and a check made that  the MAF output follows this changing flow with appropriate figures.
But how to tell the difference between a dirty MAF and a dirty stove ? (  I think I can answer that one )

PS Joe : you should have mentioned that you had to break the glass on that bulb.


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## Joe into Physics (Nov 27, 2017)

Hello Monica ... You could say that the sensitivity of my light-bulb-filament anemometer would suffer if you don't break the glass bulb first. 

As for Ravelli software, that's up to them, and it seems that something better than an "MAF sensor error" message is overdue.  As for a firmware check of the thermistor, I would expect that unless the stove is extremely dirty or there is a significant obstruction in the air passageways entering and leaving the stove, then the fan output should be much less sensitive to accumulating dirt than the MAF sensor.  If that's true, then your suggestion of a self-calibration, running the fan from low to high and checking the sensor output, ought to work.  Also, to a limited degree the firmware could adjust for changing sensitivity of the MAF sensor, until the level of needed adjustment is high enough to suggest significant problems with the system.  It's always good to have a system like that tell you SPECIFICALLY what is going bad, along with a severity code, for example: Code 1: Have the technician check this at your next regular service.  Code 5: Don't operate the stove, you might burn down the house.


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## Monica in France (Nov 28, 2017)

I like your idea of using the results of the start-up test to calibrate the session.
Setting the motor with ( lets say ) three different voltage/currents and comparing the fan speed and airflow that gives. The fan speed tells you when the stove needs cleaning , the correlation of fan speed and airflow tell you when the MAF needs cleaning. And have a ' squeaky clean' calibration in the menu to set the reference figures after installation?
As an engineer I like your 1 - 5 level error messages but I can not see the sales people agreeing .
< Warning – limp mode – Stop > sounds easier to grasp.
Could the the next generation have a CAN interface for the technician ?


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## Joe into Physics (Nov 28, 2017)

A CAN interface, so you can actually query the system and get a record of what's been going on, and maybe even make adjustments and updates???  In other words, turn this into a 21st century appliance.


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## Mt Bob (Nov 28, 2017)

Just buy one of these,add any sensors and programming you want.http://www.naturela-bg.com/en/product/39-npbc-v2-controller-for-pellet-burner


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## Ssyko (Nov 28, 2017)

Damn I want one!


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## Mt Bob (Nov 28, 2017)

Ssyko said:


> Damn I want one!


There are several more,but are on other computer,could find them later if you want the info.


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## Ssyko (Nov 28, 2017)

If and when you get a chance Ill save them on my pc instead of this phone


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## Monica in France (Nov 28, 2017)

That is really  interesting , a 'MegaSquirt' for pellet stoves.        Bookmarked.
Every bell and whistle but no MAF control !  ( no CAN either , just RS232 )
I had a good look because that could be just what I want to bring my stove into the 20th century.
The Ravelli hardware is good but their firmware does leave a lot to be desired.


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## Mt Bob (Nov 28, 2017)

http://www.newpellet.com/web/cataloghi/catalogo_ENG11.pdf http://www.fumis.si/en/about-fumis/fumis-combustion-controllers/fumis-alpha


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## Ssyko (Nov 28, 2017)

Now that is prices without the import and broker fees but that is on my Christmas list


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## Ssyko (Nov 28, 2017)

thanks for the links Bob


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## Mt Bob (Nov 28, 2017)

Ssyko said:


> thanks for the links Bob


 No problem. almost bought one of the ebay ones,to play with ,but money is tight right now.


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## Ssyko (Nov 28, 2017)

I here ya. i need to get my extra stoves done so i can make some $$$ back.


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## Tails1 (Nov 29, 2017)

bob bare said:


> Just buy one of these,add any sensors and programming you want.http://www.naturela-bg.com/en/product/39-npbc-v2-controller-for-pellet-burner



I want one of these too!


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## jerrieric (Sep 25, 2018)

bob bare said:


> http://www.newpellet.com/web/cataloghi/catalogo_ENG11.pdf http://www.fumis.si/en/about-fumis/fumis-combustion-controllers/fumis-alpha


Ravelli rv100c 09 air flow issue. Read forum and cleaned sensor. Problem fixed, thx forum members!!


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## jerrieric (Oct 2, 2018)

jerrieric said:


> Ravelli rv100c 09 air flow issue. Read forum and cleaned sensor. Problem fixed, thx forum members!!


Well after running for a day and a half I'm getting the 09 air flow meter issue again any suggestions


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## Manly (Oct 4, 2018)

jerrieric said:


> Well after running for a day and a half I'm getting the 09 air flow meter issue again any suggestions



From your post I am assuming you cleaned but did not replace the sensor. If that is so and all pipes, tubes and stove compartments are thoroughly cleaned, you might want to install a new debimeter. I have a fairly new Francesca that started going into air flow alarm in its second season. I ran into this thread as well as others with good advice. I cleaned all my vents, ports, air tubes, everything spotless. Cleaned the sensor even though it looked clean. Installed a new vacuum switch. Finally I ordered a new flow sensor from Woodsman and it’s been flawless and trouble free since. It was a PIA trouble shooting but I did gain a good understanding of the workings of the unit.


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## jerrieric (Oct 4, 2018)

I just returned from a ride over to Woodman's. Fortunately it's not that far away maybe an hour and a half . But it was sure hard to find. I installed a new air flow meter and it's so far so good. I'll keep you posted.


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## jerrieric (Oct 4, 2018)

why do these meters go bad? 1st season and worked at end of 1st season but got the 09 meter flow error after a few days of running this season.


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## Manly (Oct 5, 2018)

jerrieric said:


> why do these meters go bad? 1st season and worked at end of 1st season but got the 09 meter flow error after a few days of running this season.



That’s about how long mine lasted before it failed. From what I have read here and on other sites, these electronic board flow meters are a common configuration in automotive and other applications. Resistors with known values changing resistance as the module heats up due to lack of air flow. That’s a very basic description of how these solid state components work to interpret air flow. When anyone of the components fails, the unit faults. I am surprised by the apparent frequency of failures of these debimeters. In my experience with these basic components under these conditions I would expect a very low failure rate and a long service life, unless they are using the lowest quality of components, which is not the norm for European manufacturers.


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## jerrieric (Oct 6, 2018)

Is there any place to buy revalli parts online? Only thing I hate about the stove is trying to find parts. I always maintain my stoves myself. Hate to pay service fees. I did find how to reset the service hours but took me awhile.


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## Manly (Oct 6, 2018)

jerrieric said:


> Is there any place to buy revalli parts online? Only thing I hate about the stove is trying to find parts. I always maintain my stoves myself. Hate to pay service fees. I did find how to reset the service hours but took me awhile.



Woodsman is where l order my Ravelli parts from. They are the closest dealer to me that stocks ample parts. I do all my own service on everything I own. Unfortunately Ravelli parts are not in great abundance in this market. I have done well by woodsman for the few things I’ve needed. How did you reset the service hours?


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## Manly (Oct 7, 2018)

jerrieric said:


> Reset service hours



Thanks. I will keep a copy with mr Ravelli files. Getting all the needed drawings and schematics has been a seek and search process. Technical documentation has not been readily available but I am in pretty good shape after a couple of years.


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## jerrieric (Oct 8, 2018)

Well it ran for a total of 8 hours, 4 hrs for 2 mornings.  Now getting the 09 error with new meter. Starting to regret buying this stove. Requested a service call. Pathetic for only running 1 season.


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## Manly (Oct 8, 2018)

jerrieric said:


> Well it ran for a total of 8 hours, 4 hrs for 2 mornings.  Now getting the 09 error with new meter. Starting to regret buying this stove. Requested a service call. Pathetic for only running 1 season.



That is certainly discouraging. As I looked back in the thread I didn’t notice if you mentioned thoroughly cleaning the stove ports and cavities, heat exchange area, as well as the exhaust discharge area and pipe. I believe you mentioned you have one full season of use so a deep cleaning would have been in order. It is my understanding if the flow meter is working properly, a true error message would indicate a restricted flow through the stove. I took my Francesca down completely cleaned everything including exhaust pipes last season when I had this problem. Didn’t do any good, that’s when I decided last thing was the flow meter itself. If it didn’t work I guess the main control board would have been next, or most likely I would have mothballed the stove and purchased something more reliable. I won’t pay 1,000.00 service charge on a 2,000.00 stove, and that’s what the incompetent crooks would charge around here. I bought the stove on sale, cash and carry, installed and set up myself. Ran great for half the first season then the auger gear motor failed. I replaced the unit with a Dayton equivalent and its been running fine until the flow meter issue the middle of last season, the second season we’ve had it. We’ll see what this year brings. I would not recommend this brand to anyone based on my experiences. Keep us posted on how your service call turns out.


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## jerrieric (Oct 9, 2018)

I did a full deep cleaning. The stove was working at end of last season so don't know what is going on. The only thing I did not do was remove the exhaust blower.


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## Manly (Oct 9, 2018)

jerrieric said:


> I did a full deep cleaning. The stove was working at end of last season so don't know what is going on. The only thing I did not do was remove the exhaust blower.



Exhaust blower shouldn’t be an issue. I did remove mine to clean but there was barely a coating on the impellers. Will be interesting to see what the “service expert” finds. I’m thinking they try changing out the control board or possibly something got mucked up in the settings.


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## Davew37529 (Oct 28, 2018)

Has anyone figured out what the solution is.  I had the same issue at start up with my Ravelli rv80.  I did a deep clean and cleaned the the flow meter.  It runs for about 4 hours and then get the same 09 error code.


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## jerrieric (Nov 16, 2018)

jerrieric said:


> I just returned from a ride over to Woodman's. Fortunately it's not that far away maybe an hour and a half . But it was sure hard to find. I installed a new air flow meter and it's so far so good. I'll keep you posted.


I love this stove. Its the fifth day without cleaning and the windows still clear and it's burning great!


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## Pelleting In NJ (Nov 16, 2018)

If people are willing to mail me their broken air-flow sensors, I will attempt to figure out if they can be repaired, with better quality parts. Send me a message through the "Conversation" feature of this forum (envelope icon next to your user name, upper right of the page), and I will send you my mailing address.


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## jerrieric (Jun 20, 2019)

The solution is to turn off the air flow meter via the console. Turned mine off October 2018 and  it ran perfectly through the entire season 2018 / 2019


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## jerrieric (Oct 10, 2019)

Ravalli came out with reprogramming bypass for the air flow meter to have the RDS work properly. Ravelli could never figure out why the air flow meter fails


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## jerrieric (Jan 17, 2020)

I reprogrammed my rv100 C based on the numbers ravelli gave me. Stove runs good but I can't run it on Power 4 or 5 because I get hot smoke error which I never got before when the air flow meter was working properly. I'm pretty discouraged at this point. Thinking about buying a new motherboard to see if that solves the issue.


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## Monica in France (Jan 18, 2020)

This thread is worrying me.
I was thinking of buying a new Ravelli RDS stove.
I like the  concept behind  RDS  - but if its implementation is not reliable or just bug ridden , I will have to find an alternative.
What is the consensus ?
What is the basic problem ?


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## TLO03 (Jan 18, 2020)

Im with this guy^ , Im thinking about getting a RV 80  but worried about reliability..


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## nbrewno (Dec 8, 2020)

Last year around this time I got the 09 air flow meter code. I pulled the sensor and looked at it under a microscope like Joe did. I found corrosion on one of the thermistors and was unable to get a good resistance reading through it. I called up North Forge Home Heating and got a new air flow meter and installed it. That seemed to fix it, weather it was actually a bad air flow meter or just needed to be cleaned, who knows. One year later, 09 air flow meter came back. So I called a Ravelli tech in the area to come take a look. He did find some minor blockages behind the lower anti-explosion doors and cleaned it all out. Did a thorough cleaning of the stove and fired it up. Code came on right away. He happened to have a new motherboard in his truck so he swapped out the motherboard. Code still present. He tested the continuity of the wire harness that connects the air flow meter to the motherboard and found no issues. Tried to order a second air flow meter but can't seem to find any in stock anywhere.... which leads me to think it's a bad part and in high demand. Moral of the story, don't jump to trying a new motherboard just yet. Do some more tests first.

I've heard a lot of talk on here about the vacuum switch effecting the way the stove operates. I was under the impression that if there was no vacuum (due to blockage in the vacuum line) that it would disconnect power to the pellet feed screw and not allow any more pellets to be dropped. So it seems to me that if it was a bad vacuum switch the unit wouldn't run at all. Instead of running in a limp mode like mine currently does while beeping code 09 every 10 minutes.

If anyone has a source for air flow meters or a better fix. I would love to hear back from you.

Thanks in advance!


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## Manly (Dec 8, 2020)

I am on my third air flow meter in just over three years. When this one fails I’ll try to program it out of the circuit. The replacements are expensive and unreliable.


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## nbrewno (Dec 8, 2020)

Manly said:


> I am on my third air flow meter in just over three years. When this one fails I’ll try to program it out of the circuit. The replacements are expensive and unreliable.



I can’t even find replacements right now. It seems all the distributors are sold out and they aren’t able to get anymore.... which is crazy to me. I also heard if you make it work without the air flow meter you risk a major fire hazard.


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## Manly (Dec 8, 2020)

The application of this device is for both performance and safety. The safety aspect air flow is also monitored by the vacuum switch.  The meter is used by the RDS system setup by my understanding. I would suspect if your stove is so clogged and dirty that it has become a hazard, I would think you would see a performance drop prior to that point, or possibly a different alarm might come in. We clean ourRavelli Francesca burn pot every time the stove is shut down, ie, daily. A quick vacuum is done regularly. Flame trap plate removed and upper tubes cleaned regularly. We’ve burned about 1.5 plus ton per year over 3 seasons. In the summer when I tear down the unit and pipes, I don’t have a lot of ash in the stove channels and moderate ash in the bottom of the stove pipe tee. I personally wouldn’t have any concern running the stove without the air meter, assuming it will run properly without it initially. Note I only burn high quality softwood pellets. Tried one bag of hardwood once. Never again.


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## Pelleting In NJ (Dec 9, 2020)

If people are willing to mail me their broken air-flow sensors, I will attempt to figure out if they can be repaired, with better quality parts. Send me a message through the "Conversation" feature of this forum (envelope icon next to your user name, upper right of the page), and I will send you my mailing address.

I think the airflow sensors fail because the hot-side thermistor "drifts" in ohmic-value-versus-temperature,  as it ages, compared to the cool side thermistor. Both thermistors are the same part, but the hot one ages more than the cool one because it is always higher in operating temperature. The higher temperature accelerates the aging drift.  I think if the two thermistors are replaced with a new matched pair, of better quality thermistors which have a lower aging drift, the airflow sensor can be repaired.

From a functional opinion, the airflow sensor is only there for maintaining efficient stove operation, it is not for any safety functions.


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## Manly (Dec 9, 2020)

Pelleting In NJ said:


> If people are willing to mail me their broken air-flow sensors, I will attempt to figure out if they can be repaired, with better quality parts. Send me a message through the "Conversation" feature of this forum (envelope icon next to your user name, upper right of the page), and I will send you my mailing address.
> 
> I think the airflow sensors fail because the hot-side thermistor "drifts" in ohmic-value-versus-temperature,  as it ages, compared to the cool side thermistor. Both thermistors are the same part, but the hot one ages more than the cool one because it is always higher in operating temperature. The higher temperature accelerates the aging drift.  I think if the two thermistors are replaced with a new matched pair, of better quality thermistors which have a lower aging drift, the airflow sensor can be repaired.
> 
> From a functional opinion, the airflow sensor is only there for maintaining efficient stove operation, it is not for any safety functions.


Have you actually repaired and tested one? I kept the failed ones.


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## Pelleting In NJ (Dec 9, 2020)

No, I have never examined or repaired one....thats why I am asking for one...


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## Blstr88 (Feb 7, 2021)

This issue is getting completely ridiculous...every year for 3 years now I've had to replace this. Now this is my 4th year. 

When I pull the sensor from my stove it literally looks black and charred. There must just be too much heat radiating that close to the pipe for that sensitive little electronic to handle? Mine can't be cleaned, its actually burned up. 

I can't find one now either - they seem to be out of stock everywhere. Ridiculous such an expensive stove that otherwise would be great is out of service from a dumb little part like this.

Has anyone successfully bypassed the flow meter from the menu? I plan to look into that tomorrow when I'm home. 

Another option I considered is when I get a new one (IF I can even find one) I'm going to actually drill a few small holes as needed in my cold air intake pipe further back from the stove and try installing the meter further down the intake pipe. I'm thinking maybe if it's further from the stove the heat won't break it down so quickly? 

Anyone ever try contacting Ravelli about this?


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## Monica in France (Feb 8, 2021)

That sounds very interesting.
Could you share more information with us ?
Is the 'charred' bit inside the inlet tube ( on the actual sensor )  or on the outside / connector side ?
What is your usual setting for the stove ?           P5 at a guess !
If this is happening I am surprised that the fuel hopper is not getting overheated as well.
My stove is pre RDS by a number of years but if the inlet pipe got that hot  I would be very worried.
I've just touched the inlet tube on my stove where the sensor would be - nearly as cold as the outside air - not surprising when you think about it !


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## Ssyko (Feb 8, 2021)

Blstr88 said:


> that sensitive little electronic to handle


its not t he air or tube it is probably the the electrical current flowing through the device  that is burning it. it looks like it is a thermister type resistor that changes resistace as air flows through it(temp change). this is a guess, i have never had my hands on one to test and there are none in my area that i have worked on.


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## Monica in France (Feb 9, 2021)

The other possibility is the direct radiation from the burn pot which is not so far away. 
In my stove there is a straight tube between the two. Obstructed by the igniter perhaps.
But if this was the case , surely the MAF would not work at all ?


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## Ssyko (Feb 9, 2021)

Well if the stove is in operation it will be drawing cooler air through the tube into the burn pot. And if it is getting that hot, there is a more serious issue going on thats way beyond my pay grade


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## Blstr88 (Feb 9, 2021)

Yeah it's drawing very cold air in from outside so I would have thought that would keep it cool. Maybe as Ssyko mentioned its not actually radiant heat, but electrical current? I'll post a picture of it. 

I found in the settings where the air flow meter is set to auto but I can't seem to actually change it to off, do I need to enter that RDS key before I can make that change? If so, any idea what the key is? Or does it vary by stove?


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## Pelleting In NJ (Feb 9, 2021)

The code is 11 to disable the "debimeter" (airflow meter).
Private message me your email address and I can send you the Tech Manuals for Ravelli RDS stoves.


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## donedeploying (Nov 1, 2021)

So... I followed most, if not all suggested cleaning of both the vacuum system & airflow sensor/"debimeter" without success... Until I reset the stove to factory default settings (user code "11"). No longer in modulation mode, pumping out the heat in working mode. I'll advise if that changes.


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## waltonb (Nov 2, 2021)

replaced the air flow meter on mine twice over the years before finding out about this setting.


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## Manly (Nov 2, 2021)

waltonb said:


> replaced the air flow meter on mine twice over the years before finding out about this setting.


I’ve just Installed my fourth replacement in five years. Unfortunately my Francesca firmware does not have the option to turn the flow meter off. My stove dates to 2010 and apparently is an early version of the RDS implementation. I recently traveled to western MA to purchase new debimeters. When I explained my ongoing issue he immediately asked if I have outside air piped into the stove. I do. He said thats what causes the failure. He has found once the cold outside air is removed the failures go away. Made sense. I’ll try running without the outside intake connected. Rather be able to turn it off in the software but not possible on my version.


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## waltonb (Nov 2, 2021)

I don't have an external air supply duct on mine, it just pulls air from the room.

This is all making me wonder what exactly the air flow meter is trying to measure for the RDS.   Is it only that the air supply is not blocked?  Or does a debimiter failure indicate the combustion/exhaust fan may be underpowered, thus making the air flow inadequate.


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## Pelleting In NJ (Nov 2, 2021)

The airflow sensor measures the amount of intake air. The RDS system uses this info to maintain a constant amount of airflow through the combustion chamber, with the goal of keeping the air-fuel ratio of the burn constant. It is like an automatic damper adjuster.

 As the exhaust path restriction increases (from ash build-up), the RDS "sees" the reduced airflow from the airflow sensor, and then increases the RPM of the exhaust fan to get the actual airflow back to the original value, thereby maintaining the same air-fuel ratio.  Eventually, when the ash restricts the burn-pot / exhaust passages enough, to the point that it can't increase the fan RPM any more to maintain a constant airflow, the clean the burn-pot alarm is triggered.

The set-up of the RDS system, where it "learns" the baseline airflow amount, of a clean, low restriction burn-pot and exhaust pipe configuration, is the RDS setup routine that is supposed to be performed when the stove is first installed.

 The airflow sensor works as follows: There are two main parts, an air temperature sensor (thermistor), and a heater (fixed) resistor. These are the two chip parts soldered to the ends of the two "fingers" of the sensor board. The control board sends current through the heater resistor, and the downstream thermistor measures the air heated by the heater resistor. The control circuit adjusts the heater power so that the thermistor measured temperature rise is constant. So, if you connect the outside air to draw cold air from the outside, the heater power is cranked up to compensate for the much colder outside air. Maybe that's why the airflow meters fail more often if you use cold outside air, the design of the heater resistor is not able to withstand the higher power dissipation, and gets brown, or burns out completely.  Probably needs a higher power rated resistor.


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## Manly (Nov 3, 2021)

Pelleting In NJ said:


> The airflow sensor measures the amount of intake air. The RDS system uses this info to maintain a constant amount of airflow through the combustion chamber, with the goal of keeping the air-fuel ratio of the burn constant. It is like an automatic damper adjuster.
> 
> As the exhaust path restriction increases (from ash build-up), the RDS "sees" the reduced airflow from the airflow sensor, and then increases the RPM of the exhaust fan to get the actual airflow back to the original value, thereby maintaining the same air-fuel ratio.  Eventually, when the ash restricts the burn-pot / exhaust passages enough, to the point that it can't increase the fan RPM any more to maintain a constant airflow, the clean the burn-pot alarm is triggered.
> 
> ...


This sounds like a very plausible explanation to these component failures. I’ve been dealing with this issue four years running. I would prefer to have outside combustion air but I will leave it disconnected and see how many seasons I get in this mode. Really wish I could disable the debimeter in the software but I’m 97% certain that option was not in the early version I have. It’s not seemingly possible to talk to a Ravelli rep that can give definitive answers on technical issues.


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## Mt Bob (Nov 3, 2021)

Pelleting In NJ said:


> The airflow sensor measures the amount of intake air. The RDS system uses this info to maintain a constant amount of airflow through the combustion chamber, with the goal of keeping the air-fuel ratio of the burn constant. It is like an automatic damper adjuster.
> 
> As the exhaust path restriction increases (from ash build-up), the RDS "sees" the reduced airflow from the airflow sensor, and then increases the RPM of the exhaust fan to get the actual airflow back to the original value, thereby maintaining the same air-fuel ratio.  Eventually, when the ash restricts the burn-pot / exhaust passages enough, to the point that it can't increase the fan RPM any more to maintain a constant airflow, the clean the burn-pot alarm is triggered.
> 
> ...


"The control board sends current through the heater resistor, and the downstream thermistor measures the air heated by the heater resistor"

I find this highly illogical, but if true, would be very inefficient, nor accurate, unless it was closed down in a very small air channel. Is it?
The way MAF (mass air flow) sensors work-- one of the "sensors" measures the temperature of the incoming air. The other (hot wire,hot film,etc) has constant voltage to it, and, as incoming air flow "steals" it's heat, the amount of current used goes up. The computer programming takes over from there,using this information. Unless Ravelli has some screwed up system.
The amount of failures seems amazing to me, Integras had this system, and many MAF sensors are original,still running, and ones that have been replaced,were not the problem with the stove.
BTY, the Integra ones were made from some parts from BMW sensors.


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## Mt Bob (Nov 4, 2021)

OK, did some research. These are made by MicroNova (Italy). Seeing better pictures,and pictures of their other products, these are simply 2 sensors, and 1 resistor. No programming chips or other items. IF you could get the specs on the sensors,they would be very easily repaired,even duplicated.
From reviews, these also have a very high failure rate in Europe.
And you can buy them for about 20 bucks,over there.
The manufacturers # is PK063.


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## Monica in France (Nov 4, 2021)

I was looking at a MAF in a car the other day.
There must be millions of them all round the world working without a problem .
 So why does the Ravelli one screw up with such regularity ?
The automobile version looked somewhat less delicate. And complete with electronics cost the same as the Ravelli's two thermistors and restistor.
I'm inclined to agree with Pelleting in NJ : the Ravelli implementation compensates for seriously cold air by frying the resistor.


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## Pelleting In NJ (Nov 4, 2021)

If people are willing to mail me their broken air-flow sensors, I will attempt to figure out if they can be repaired, with better quality parts. If they can also send me a new sensor, that would also help me investigate this. I will return both sensors to you when I am done with my investigation.  I am an Electrical Engineer with a well equipped lab bench.

 Send me a message through the "Conversation" feature of this forum (envelope icon next to your user name, upper right of the page), and I will send you my mailing address.


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## Mt Bob (Nov 4, 2021)

Pelleting In NJ said:


> If people are willing to mail me their broken air-flow sensors, I will attempt to figure out if they can be repaired, with better quality parts. If they can also send me a new sensor, that would also help me investigate this. I will return both sensors to you when I am done with my investigation.  I am an Electrical Engineer with a well equipped lab bench.
> 
> Send me a message through the "Conversation" feature of this forum (envelope icon next to your user name, upper right of the page), and I will send you my mailing address.


GM. Long time,life has kept me busy.
Yes,if it is usually the resistor failing,all you would need is for someone to measure a new one. And, as you know,traces can be fixed. I contacted the manufacturer, and they basically lied, I aske for the specs on the thermistor chips, and they said that is the property of the stove manufacturer. Well, that same part number is used interchangeably in other stoves and devices,even BBQ's! Over in Europe,anyway. I have found them as cheap as 23 bucks, over there(on the net). As it is a simple board,with 3 smt devices, they probably cost less than 2 bucks to mass produce. I see the price now for places in USA that have them is 90 bucks. Is there a way to identify the thermistors?  I do not think they are marked like other SMT devices.


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## Pelleting In NJ (Nov 4, 2021)

I should be able to identify the thermistors by measuring their temp-versus-resistance curve, and then matching that curve up with an available substitue part.


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## Mt Bob (Nov 4, 2021)

Pelleting In NJ said:


> I should be able to identify the thermistors by measuring their temp-versus-resistance curve, and then matching that curve up with an available substitue part.


Ah, but with a new functioning part,I assume? Will se if I can find a cheap one for you, as the ones I have found in the USA are 90 bucks. BUT, do those stoves function OK when people put them in the mode to bypass the sensor?


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## Pelleting In NJ (Nov 4, 2021)

If the RDS function is disabled in the menu, the stove operates fine, like the older non-RDS models do. The stove just will not try to maintain a constant air-fuel ratio as the burn pot and exhaust passages get more restrictive due to ash build-up. The bottom line is that a non-RDS stove will require cleaning more often than if RDS is functioning.


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## Mt Bob (Nov 4, 2021)

Pelleting In NJ said:


> If the RDS function is disabled in the menu, the stove operates fine, like the older non-RDS models do. The stove just will not try to maintain a constant air-fuel ratio as the burn pot and exhaust passages get more restrictive due to ash build-up. The bottom line is that a non-RDS stove will require cleaning more often than if RDS is functioning.


AH so there is great benefit to it working, much like having the latest prom in an Integra.


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## Mt Bob (Nov 6, 2021)

Pelleting In NJ said:


> If the RDS function is disabled in the menu, the stove operates fine, like the older non-RDS models do. The stove just will not try to maintain a constant air-fuel ratio as the burn pot and exhaust passages get more restrictive due to ash build-up. The bottom line is that a non-RDS stove will require cleaning more often than if RDS is functioning.


Got a sensor coming from Europe, but looks like will be 3-4 weeks to get here.Can send to you for testing when it arrives. Was 40 bucks,including delivery, cheapest I could find,delivered to USA.


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## Pelleting In NJ (Nov 9, 2021)

I received two failed airflow sensors, sent to me by Manly...thanks!!
One sensor was his original that came with the stove (#1), which was later replaced by sensor #2.

Here are my observations so far:

*Sensor#1*
-  Sensor #1 has minimal, to no,  "browning" ("burnt")  areas from high temperature exposure.
-  No cracked solder joints were observed.
-  The Heater resistor R1 measures correctly at 750 Ohms.
- Thermistor RT1 (airflow outlet) measures a correct 10K at room temperature.
- Thermistor RT2 (airflow inlet) measures an incorrect 15.5K Ohms at room temperature.

*Sensor #2*
- Sensor #2 has significant "browning" ("burnt") areas  from high temperature exposure, on the edges of the finger PCB. It is not browning of the the electronic components, but of the PC board itself. As it is only on the edge of the board fingers that face the airflow outlet, that indicates that somehow, hot combustion air from the firebox must have flowed backwards through the intake tube, and cooked the edges of the board. The only way that can happen is if there is a wind gust that drives air backwards through the flue, overcoming the combustion blower,  and then out the cold air intake.
-  No cracked solder joints were observed.
- The Heater resistor R1 measures correctly at 750 Ohms.
- Thermistor RT1 (airflow outlet) measures a correct 10K at room temperature.
- Thermistor RT2 (airflow inlet) measures an incorrect 13.2K Ohms at room temperature.

Thoughts so far:
- The airflow meters seem to fail when the two identical thermistors drift apart too far. I think the stove, when it is first turned on, checks the two thermistors, and if the resistance values don't match (they should match when they are both at the same temperature), the stove flags the "Bad Airflow Sensor" alarm.  I am not sure what is the root-cause of the value drift of one of the thermistors (RT2 in both units I tested).
- I don't think the overheat browning issue is the cause of the RT2 value drift, as the brownest finger is where RT1 is located, and it's value is still correct.
- I think I found the manufacturer of the thermistor parts used by Ravelli/Ecoteck (really MicroNova, the maker of the airflow sensor and stove control board). I need to do some more testing to then be able to select a suitable equivalent replacement part, to repair these boards. Stay tuned.....


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## Pelleting In NJ (Nov 9, 2021)

Blster88:  Please post a close-up picture of your "burnt" airflow sensor.


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## Manly (Nov 9, 2021)

I’m glad you received them in a timely fashion. The meter that is darkened is the only one of my 3 failed boards that will not allow the stove to start. The others allow full fire then go into a low run alarm state.


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## Mt Bob (Nov 9, 2021)

Here is what I am willing to say is the same sensor,same specs, except it is on a ribbon cable,AND uses old style through hole thermistors. Searching net,I do not see high failure rates as reported with the Ravelli one.It is used in almost all             La Nordica Extraflame pellet stoves.


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## Mt Bob (Nov 9, 2021)

Links-









						PORDET STOVE DEBIMETER NORDICA EXTRAFLAME
					

SENSORE FLUSSO ARIA ASPIRATA STUFA PELLET EXTRAFLAME




					www.grelettrofiamma.it
				





			https://prontostufe.it/en/flow-meter-sensors-circuit-boards-and-probes/739-flat-cable-depression-sensor.html
		

Amazon product


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## Pelleting In NJ (Nov 9, 2021)

Yes, that looks like an earlier version, with thru-hole parts, before the surface mount version that I am investigating. Even the electrical pin-out is the same.

I think the surface mount thermistor chips that are currently used are the problem. They have an oddball construction from every other thermistor chip, which may explain their poor stability (value drift problem).


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## Mt Bob (Nov 9, 2021)

Pelleting In NJ said:


> Yes, that looks like an earlier version, with thru-hole parts, before the surface mount version that I am investigating. Even the electrical pin-out is the same.
> 
> I think the surface mount thermistor chips that are currently used are the problem. They have an oddball construction from every other thermistor chip, which may explain their poor stability (value drift problem).


Yep,I think you are on to something.A good fix might be going back to old style,easy to do.


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## Pelleting In NJ (Nov 9, 2021)

The easy fix is to replace the two thermistor chips with better quality parts. Each thermistor costs around a dollar.


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## Mt Bob (Nov 9, 2021)

Pelleting In NJ said:


> The easy fix is to replace the two thermistor chips with better quality parts. Each thermistor costs around a dollar.


Agreed


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## Pelleting In NJ (Nov 9, 2021)

I just noticed a typo in my previous post (#99)of the measurements, the R1 heater resistors are 75 Ohms, not 750 Ohms.


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## Pelleting In NJ (Nov 27, 2021)

Update: I received a good airflow sensor from "Monica in France" (thanks!),  I will test it and complete my evaluation shortly.  I think I can fix these with better longer-lasting parts. Stay tuned.


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## Mt Bob (Nov 27, 2021)

Pelleting In NJ said:


> Update: I received a good airflow sensor from "Monica in France" (thanks!),  I will test it and complete my evaluation shortly.  I think I can fix these with better longer-lasting parts. Stay tuned.


The new one I ordered came here yesterday.


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## Manly (Nov 27, 2021)

Very exciting 👍🙂. I am dependent on these parts since my software version does not have provision to disable the debimeter.


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## Mt Bob (Nov 27, 2021)

Manly said:


> Very exciting 👍🙂. I am dependent on these parts since my software version does not have provision to disable the debimeter.


While looking for something else,I just found Earth Sense Energy Systems has reduced the price of them from $80 to $60, in case you want to get a spare.


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## Manly (Nov 27, 2021)

Mt Bob said:


> While looking for something else,I just found Earth Sense Energy Systems has reduced the price of them from $80 to $60, in case you want to get a spare.


Thanks.


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## Pelleting In NJ (Dec 20, 2021)

Update: The better quality replacement thermistors have been identified, and an order placed. I should have these parts in about a week, and then I will install them onto the two failed sensor boards that Manly sent me.


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## Dccustoms6 (Dec 29, 2021)

Pelleting In NJ said:


> The code is 11 to disable the "debimeter" (airflow meter).
> Private message me your email address and I can send you the Tech Manuals for Ravelli RDS stoves.


Hello! Happy After holidays haha. You had mentioned you had a tech service book for the ravellis with the RDS system?  I have  a RV80 ( that has almost 11000 hours on it at 3 years old haha. It does have a few issues and would love if you had the manual?  Thank you Brian Parsons

Dccustoms6@gmail.com


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## Pelleting In NJ (Jan 22, 2022)

The repaired airflow sensors, with new and hopefully more durable thermistor parts have been sent to Manly....he will see how they work.


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## Manly (Jan 27, 2022)

Pelleting In NJ said:


> The repaired airflow sensors, with new and hopefully more durable thermistor parts have been sent to Manly....he will see how they work.


Update. The repaired/upgraded flow meters arrived today. One has been installed and the outside air reattached. The Francesca is running as a primary heat source.  Any change of status on this stove will be reported here. We are heading into real winter now.


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## waltonb (Monday at 5:40 AM)

update:  on the old rv-80, during the pandemic I could not get the part anymore... desperate, I finally figured out that I could set the RDS to ignore the air flow sensor completely..  and it's been running fine this way for a couple of years now.


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## Pelleting In NJ (Monday at 12:33 PM)

Manly: Any update on the repaired airflow sensor?


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## Manly (Tuesday at 9:41 AM)

Pelleting In NJ said:


> Manly: Any update on the repaired airflow sensor?


The repaired debimeter (air flow sensor) is working wonderfully. It was installed about mid season last year and has been running great ever since.  This is the longest run we’ve ever had with this stove since installation. This small Ravelli Francesca provides 50% of our heating requirements. Our Francesca is apparently an early version of the RDS system as it has the old style 7 button keyboard and archaic looking graphic screen. There is definitely no turning off the flow meter in the firmware. This repaired flow meter is a big problem solved for our household. Thank you Pelleting in NJ for your time and skill on this matter. Our  original lemon of a stove is now a real peach🍑


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## Pelleting In NJ (Tuesday at 11:30 AM)

Glad to hear!


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