# Ravelli Francesca error code help please



## Manly (Jan 12, 2018)

I received a "drought insufficient" #13 alarm error code a couple of days ago. I have been cleaning the stove frequently, but apparently not deep enough. All the documentation I have on ravelli stoves does not specifically address this alarm error code. I would be grateful for any details regarding this particular alarm and cause.  Jim


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## Pelleting In NJ (Jan 12, 2018)

Is your Francesca the newer RDS model?


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## Manly (Jan 12, 2018)

Pelleting In NJ said:


> Is your Francesca the newer RDS model?



I purchased the stove new a few years ago but just installed last year. I am guessing the dealer had it a while as it was an older model close out. Documentation is sparse. It is not remote controllable and I don't think it has the RDS.  It does have the multitude of adjustments and I do see there is a drought (draft) adjustment I recall making during the initial setup. I will try increasing the % of draft. My concern was that I have not had a problem up to this point this season. The stove and pipes were cleaned before this season and we have only burned about 2/3 ton thus far. I found it odd that the alarm is specific with a number assignment yet I cannot find a reference to this code in any literature. Lost in translation I suppose.


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## Pelleting In NJ (Jan 12, 2018)

Does your control panel have 3 buttons or 7?


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## Manly (Jan 12, 2018)

Pelleting In NJ said:


> Does your control panel have 3 buttons or 7?



7 control buttons


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## Manly (Jan 13, 2018)

Manly said:


> 7 control buttons



Increasing the draught setting made no difference. The stove goes into alarm shortly after the full startup cycle. The flame, burn pot and everything looks great, same as it always has. I suspect a sensor or alike is malfunctioning. Time to disconnect and open her up. Thankfully it's not frigid like last week.


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## Pelleting In NJ (Jan 13, 2018)

From what I know, 7 button is the older non-RDS model.....and my technical manual for non-RDS stoves does not have an error code #13...odd......because in the RDS Manual there is an Alarm Code #13 : "Insufficient Draft Alarm" which can be caused by an open firebox door (or a bad door gasket), or a clogged burn pot, or clogged exhaust passages (in the stove) or restricted flue.

Sounds like you have an RDS stove, despite the type of control panel you have,  and the internal stove exhaust passages, or your flue, needs a good cleaning. Do you have an outside air connected? If so, also check that for any obstruction.

Another possibility is that your airflow sensor (located in the outside air intake pipe) needs cleaning, or is on its way out....

Can you post a picture of your control/LCD panel?


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## Manly (Jan 13, 2018)

Anyone have any detailed information on the logic sequence for the start and run cycle for the ravelli Francesca. I get a draught insufficient alarm after the stove goes through the complete start cycle and appears to be running great. The alarm comes in at the exact same time on each run. It did initially start alarming intermittently but quickly got to this point. I completely cleaned the stove, ports and pipes even though it eas pretty clean. Checked the vacuum switch and it seems fine, as well as the tube. I would think if the vacuum switch wasn't sensing flow I would never get to a full run cycle. Door gaskets look fine. I am at a lose. This stove has been performing nicely up to this onset. Thanks for any suggestions or input.


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## Manly (Jan 13, 2018)

Pelleting In NJ said:


> From what I know, 7 button is the older non-RDS model.....and my technical manual for non-RDS stoves does not have an error code #13...odd......because in the RDS Manual there is an Alarm Code #13 : "Insufficient Draft Alarm" which can be caused by an open firebox door (or a bad door gasket), or a clogged burn pot, or clogged exhaust passages (in the stove) or restricted flue.
> 
> Sounds like you have an RDS stove, despite the type of control panel you have,  and the internal stove exhaust passages, or your flue, needs a good cleaning. Do you have an outside air connected? If so, also check that for any obstruction.
> 
> ...



Pic attached I think. I have cleaned everything. Did determine the stove is shutting down due to the vacuum switch contact not opening. When I removed the switch it seems to operate properly with very minimal suction needed to operate the switch. I was surprised the unit would cycle all the way to a full run without the switch opening. If the switch is disconnected electrically it will not feed. Needs a closure to start and an open circuit to maintain a run. I guess I am going to have to remove the pipe and adapter to see why I am not getting suction through the tube. I can blow through it easily but that only verifies the plastic tube. I am leaning towards exhaust passages at this point. My schematic does not show air flow sensor, only the vacuum, smoke and temp sensors.


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## Manly (Jan 15, 2018)

At a loss here. Disassembled the stove for a deep cleaning. Removed the exhaust fan, opened the clean out ports upper and lower. Vacuumed everything out although I was surprised how little soot was actually inside. This stove has had about 1 ton through it since new. The flue pipe and cap are clear and clean. The vacuum tube seems unobstructed but the vacuum switch doesn't activate. When I removed the switch it will transfer the contacts with the minimalist amount of suction. The electrical contacts do switch open as verified by meter. When I jumper the vacuum switch wires to run the stove and the tube attached to the switch, the switch never transfers as verified by meter. This still seems to be a lack of vacuum (draft) issue but I can't quite see how. I hate to buy a new switch if not needed. Any suggestions appreciated.


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## Pelleting In NJ (Jan 15, 2018)

Did you try cleaning out the metal nipple (on the exhaust fan housing) where the vacuum tube connects to?  Did you clean out the inside of the exhaust fan housing (remove the fan motor by removing the 5 or 6 philips head screws around the smaller metal motor mounting plate).


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## Monica in France (Jan 15, 2018)

If my Ravelli Stove had RDS , I'm pretty sure I would have got a similar message recently.
It was clogging up every 24 hours , this was after a 'deep' clean. But obviously not 'deep' enough.
Your stove looks very similar to mine , and I wonder if it has the same weak spot somewhere up in the heat exchanger at the top.
It was only after the umpteenth clean around those tubes that it suddenly started to function correctly- as you can't see what you are doing - I have no idea what I finally did to remove the blockage.

If you are sure that every thing is clean , I would suggest you follow " Pelleting in NJ" s  suggestion and look at the M.A.F sensor
There was an interesting thread on the subject last November (? +/-) .
They need cleaning as well apparently. A fact which is far from obvious.

Has anyone found the ideal tool for cleaning around  those heat exchanger  tubes ?


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## Manly (Jan 15, 2018)

Pelleting In NJ said:


> Did you try cleaning out the metal nipple (on the exhaust fan housing) where the vacuum tube connects to?  Did you clean out the inside of the exhaust fan housing (remove the fan motor by removing the 5 or 6 philips head screws around the smaller metal motor mounting plate).



I did clean the nipple with a pipe cleaner. Today I removed and brushed all the exhaust pipes, cleaned the internal exhaust again as well as blew it out with a leaf blower. Exhaust fan motor was removed yesterday and cleaned. My unit has wing nutted screws around the perimeter to remove the entire plate. After all this the vacuum switch still would not switch. I purchased a new switch, hooked it up to the tube for testing, and it did transfer the contacts once the fan ran a short bit. I put the entire unit back together, checked my settings and fired her up. Shortly there after I got a depress alarm #8. I am guessing this came as the vacuum switch opened. I know it's not a blocked flu, the vacuum switch is new, and I am waiting for the unit to finish final cleaning to check the door switch, which I highly doubt. This is starting to become a pain. I wish I could get a hold of a wiring and logic diagram that actually shows the sequence of operations, permissive, etc. I purchased the vacuum switch from the very unrepeatable dealer where I purchased the stove, and all their service people would do is agree with me that they supplied lousy documentation. They said the problem could be almost anything. I would trash the stove before I threw away money on their incompetence. But that is a different issue. I did find out the stove was build in 2012. I purchased it new at the end of 2014. The dealer said it is definitely not RDS, but when i power up the stove the screen says ECO RDS. There is nothing consisten on the stove. Thanks for all the input from the board users here and I will keep on plugging away.


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## Manly (Jan 15, 2018)

The door limit switch seems fine. It operates properly and if I leave the door open the auger will not start, so I'm guessing it is ok.  One thing that baffles me is wiring on the vacuum switch. The circuit is wired through a normally closed contact, or so I believe it was when I removed it. This completes the circuit and allows the unit to go through the start cycle. As soon as the vacuum pressure is met, the contact opens, and this is when I am getting the depress alarm #8. Again with the limited diagram I have I don't see any other devices in this circuit to chase after.


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## Manly (Jan 15, 2018)

Monica in France said:


> If my Ravelli Stove had RDS , I'm pretty sure I would have got a similar message recently.
> It was clogging up every 24 hours , this was after a 'deep' clean. But obviously not 'deep' enough.
> Your stove looks very similar to mine , and I wonder if it has the same weak spot somewhere up in the heat exchanger at the top.
> It was only after the umpteenth clean around those tubes that it suddenly started to function correctly- as you can't see what you are doing - I have no idea what I finally did to remove the blockage.
> ...



Where is the M.A.F sensor located? My diagram doesn't identify it.    Thanks


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## Ssyko (Jan 15, 2018)

Just out of curiosity, does your vac switch have 2 nipples? If its a dual nipple 1 side is used for pressure the second side is used for vacuum. I dont know the stove well at all but if the hose is on the wrong side it wont trigger the auger. And normally a vac switch is open. After stove starts and combustion blower starts it creates the vacuum in the chamber wich closes the circuit for the auger. The start up program controls the stove till all the components have met their respective requirements. Then the stove goes into user mode where you can control voltages and feed rates.


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## rich2500 (Jan 15, 2018)

Manly said:


> Where is the M.A.F sensor located? My diagram doesn't identify it.    Thanks


It,s located on the intake air inlet several inches in from the end that you would hook up the metal pipe to go outside


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## Manly (Jan 15, 2018)

Ssyko said:


> Just out of curiosity, does your vac switch have 2 nipples? If its a dual nipple 1 side is used for pressure the second side is used for vacuum. I dont know the stove well at all but if the hose is on the wrong side it wont trigger the auger. And normally a vac switch is open. After stove starts and combustion blower starts it creates the vacuum in the chamber wich closes the circuit for the auger. The start up program controls the stove till all the components have met their respective requirements. Then the stove goes into user mode where you can control voltages and feed rates.



I do have a dual function vac switch. It is connected to the vacuum side and I have verified it is functioning at this time. The contact sequence you describe makes more sense to me than using the closed contact I am presently connected to. I thought that was how the old switch was connected but I may be mistaken. It's too late tonight but tomorrow evening l will swap onto the open contact and give it a try. I was thinking this was going to be my next move anyway. Than thank you for your support.


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## Manly (Jan 16, 2018)

Manly said:


> I do have a dual function vac switch. It is connected to the vacuum side and I have verified it is functioning at this time. The contact sequence you describe makes more sense to me than using the closed contact I am presently connected to. I thought that was how the old switch was connected but I may be mistaken. It's too late tonight but tomorrow evening l will swap onto the open contact and give it a try. I was thinking this was going to be my next move anyway. Than thank you for your support.



Unfortunately I'm still in the same situation. The vacuum switch contacts definitely use the NC contact which opens when the blower starts. Using the NO contact the auger never starts. I also checked the old switch and the NO terminal never had a spade pushed on it. Shiny and flawless like a mirror. I did verify the new switch operation with a meter and it works perfectly, where the old switch definitely did not work. Still get no depress alarm once the unit goes through a full startup cycle. I am going to double check all my terminal connections. Besides the 2 safety switches, the only other permissive devices I see are the hopper temp sensor and the sensor in the air intake pipe. Does anyone know what type of devices these are, i.e., RTDs, thermocouple, etc. I would like to start jumping things out to see if I can maintain a run before I start changing out parts. It is difficult without a real schematic. The picture line diagram they supply doesn't even show all the components or describe sequence of operation. Again thanks for any input or suggestions.


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## Monica in France (Jan 17, 2018)

I looked at the Ravelli RDS manual that I had downloaded many moons ago. Found on a canadian web site if I remember correctly.
Your error n°13 is ( as stated by "pelleting in NJ" ) a draft problem.
Not enough air going past the MAF.
A depression problem would give you error N° 8.
If you can't find this manual on-line ,  I can send it too you.
I probably googled "ravelli RDS manual".

Re-reading the other thread  I referenced in another posting (Ravelli RV80 - Problem: Air Flow Meter), he had error N° 9 for a sensor problem.
There was a thread "RV100 Ravelli alarm 17 No Flow alarm" earlier this year. Error N° 17 is not mentioned in the RDS manual I have.

Imagine the air entry passage behind the burnpot is blocked. What would signal the problem first ? the MAF or the depression ?
This does not explain why the stove ignites correctly. If this passage was blocked it would not ( experience talking).
So please , keep posting , I for one would like to know what the problem is.


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## Manly (Jan 17, 2018)

Monica in France said:


> I looked at the Ravelli RDS manual that I had downloaded many moons ago. Found on a canadian web site if I remember correctly.
> Your error n°13 is ( as stated by "pelleting in NJ" ) a draft problem.
> Not enough air going past the MAF.
> A depression problem would give you error N° 8.
> ...



My original alarm was the #13. Replacing the vacuum switch, which was definitely not working, has eliminated the #13. I now get a #8 depression alarm after the stove goes through a normal startup cycle. I am going to remove and clean the MAF sensor next. I have completely cleaned and blew out the stove from air intake all the through including cleaning the entire flue pipe. I am thinking the MAF sensor could be dirty from the cleaning process. I do have various versions of Ravelli manuals that I have found on the web. They all seem to contain bits of information that relate to my stove, but I have not found one manual that addresses my stove and its individual components. I haven't found a diagram that shows the MAF. According to dealer I purchased the stove from, the unit was manufactured in 2012 and is not a RDS system. When I power up the stove the LCD screen starts with "ECO RDS" 2009, then comes up with something like rev 2015. I have not seen a diagram or picture that shows the exact control panel layout I have. It seems like Ravelli sort of blended their technologies from one year to the next with no manual as built for each revision. Anyway I appreciate yours and others input and I will keep plugging away until I find a resolution. I purchased the stove new but didn't pay a whole lot for it. I wouldn't have the dealer come out to look at it because they will charge at least 30% of what I paid them for the stove. They are just that type of dealership. The auger motor failed after about a 1/2 ton of pellet burning. Its been running well up to this latest failure, about 1 ton of pellets. I clean the burn pot and vacuum the inside between each ignition. When I did my deep cleaning this week the stove was not very dirty inside or the flue pipe.


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## Monica in France (Jan 17, 2018)

I've been looking at that manual again. ( for installers in 2012 , updating the original RDS system with V3 of the firmware)
The firmware should be initialized by the dealer when he installs the stove !
I assume yours did not - as he thinks the stove is not RDS - so you are presumably running with non optimised parameters.
Will this make any difference ? Certainly not at the moment !

But I was concentrating on the error messages . Why do you get the depression alarm after it has gone into "work" mode ?

With a faulty vacuum switch the stove should have refuse to ignite. It certainly stopped the auger moter as they are wired in series ,
so where did the pellets come from ?

But now you are sure it works , with a pressure difference , but it only has that pressure difference during the ignition period.
After that it cuts out.
This must mean that the pressure difference is only generated during the start up - when the fan is going full blast.
As soon as it goes into work mode and the fan slows down, it does not create the necessary pressure difference.
This means something is preventing the air flow.

This logic can be put to the test : just short circuit the vacuum switch and see if you still get an alarm after entering work mode .
There should be no alarm n° 8 and the flame should be extremely lazy.

Another easy test would be to pump compressed air into the air intake and see if the vacuum switch cuts in  - or not.


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## Manly (Jan 17, 2018)

Monica in France said:


> I've been looking at that manual again. ( for installers in 2012 , updating the original RDS system with V3 of the firmware)
> The firmware should be initialized by the dealer when he installs the stove !
> I assume yours did not - as he thinks the stove is not RDS - so you are presumably running with non optimised parameters.
> Will this make any difference ? Certainly not at the moment !
> ...



I had previously jumpered the vacuum switch and the stove would start and run for 10 minutes or so then go into a #13 alarm, draught insufficient. This was my initial alarm which led me to change the vacuum switch. I have the air tube on the vacuum, or suction side of the switch, and the wires on the normally closed contacts. I believe this is how the original pressure switch was connected. I do get suction and this new switch does transfer contacts when I put a meter on it. I guess it is possible the pressure switch drops out after the ignition phase. I can't see how I would have air flow restriction since I cleaned all the internals, exhaust fan and chamber, flue pipes and blew it out.


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## Ssyko (Jan 17, 2018)

Manly is the stove a positive pressure fire chamber or is it a vacuum? Conbustion blower sucks air through or blows into the fire chamber? Im just trying to understand your stove


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## Manly (Jan 17, 2018)

Ssyko said:


> Manly is the stove a positive pressure fire chamber or is it a vacuum? Conbustion blower sucks air through or blows into the fire chamber? Im just trying to understand your stove



To the best of my knowledge the blower pulls air through the combustion chamber. The air intake pipe opens into the combustion chamber below the burn pot. The heated air and smoke gets pulled up and around the heat exchanger tubes and out the exhaust.


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## Ssyko (Jan 18, 2018)

Have you cleaned the debimeter in the intake tube? I know its been an issue with some other ravelli owners?


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## Manly (Jan 18, 2018)

Ssyko said:


> Have you cleaned the debimeter in the intake tube? I know its been an issue with some other ravelli owners?



That is my next step. I won't be able to get to it until Friday night. I am hoping that is the issue. I am running out of options to try. At that time I am also going to double check all my wiring terminations. I sure wish I could get a hold of an actual wiring diagram and sequence of logic/operation for this stove. Apparently they are near non existent or just hard to find. I do greatly appreciate all the input I have received from the forum members here.


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## rich2500 (Jan 18, 2018)

I have a wiring diagram for my Francesca which I would gladly send you but I don't know how similar it would be for your stove. mine is a 2015


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## Monica in France (Jan 18, 2018)

Ssyko et al,
these stoves are mechanically very simple.
The air comes in with a single tube. In the model under discussion this tube has a MAF in it.
It enters a sealed box around the burn box by the tube with the igniter in it.
The burn box naturally has a hole opposite this tube and has the usual holes on the bottom ( for primary combustion)  and sides ( for secondary combustion).
The combustion heat rises into a 'forced air' heat exchanger at the top and escapes at the sides ( where cleaning is a nightmare ) ,
going down into a cavity below the hearth area.
These passages going down the sides have removable covers in them , but no real access to the top edge where my troubles always start.
The exhaust fan sucks from this last box into the flue.
The flue has a depression sensor just "behind" the flue flow to assure that the smoke is being evacuated.( and that wind down the flue is not stopping the flow.
There is another "basic" security : a temperature sensor attached to the pellet hopper.
They added door switches and the like as the years went by.
Their basic firmware is keeping the revs of the exhaust fan correlated with the supply of pellets controlled by the auger motor.
When they realized this was only valid up to a point they added the MAF.

I think the idea of a positive pressure fire chamber is probably against european law , certainly against what passes for common sense here.
The more fail safe the better . Like brakes on trains.
Certainly French law stipulated the depression sensor on the flue of my gas boiler.


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## Ssyko (Jan 18, 2018)

Lol yeah machanicly simple but over engineered on software and controls. My reference to positive pressure was just to try and wrap my head around the vacuum switch disconnects when blower starts. That just doesn’t make sence to me. But i dont know the software either.


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## Monica in France (Jan 18, 2018)

My stove is the generation before yours but it is visually very similar.
I post a picture of my depression sensor. made by Honeywell.
You can see the connections well enough to see if yours are the same.
But please , no comments on all the pellets that need vacuuming up !

In my wiring diagram this is in series with the auger feed.
Implying the depression gives the contact.

I do not believe that Ravelli would have programmed the MAF to override the basic firmware parameters to such an extent that it causes a shutdown situation.
But have you looked at the 'stove status' display just before the alarm sets off.
 What are the exhaust revs ? My logic says they dip just before it beeps.


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## Manly (Jan 18, 2018)

Ssyko said:


> Lol yeah machanicly simple but over engineered on software and controls. My reference to positive pressure was just to try and wrap my head around the vacuum switch disconnects when blower starts. That just doesn’t make sence to me. But i dont know the software either.



The poor documentation supplied shows the power to the auger going through a N.C. on the vacuum switch. This same wire feeds back to the control board. This is where I presume the control logic comes into play. The N.C. contact allows the pellet auger to start immediately to fill the burn pot. The exhaust/combustion fan then starts. The vacuum switch contact then opens, and at this time the logic sends power to the auger via the common wire at the control board. If the vacuum switch contact should transfer or fail, I suspect the power coming back through the N.C. contact is somehow detected by the logic and a #13 insufficient drought alarm is generated. This is all conjecture from what I have seen with this stove. I have no documentation or description on the logic control.


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## Manly (Jan 18, 2018)

Monica in France said:


> My stove is the generation before yours but it is visually very similar.
> I post a picture of my depression sensor. made by Honeywell.
> You can see the connections well enough to see if yours are the same.
> But please , no comments on all the pellets that need vacuuming up !
> ...



My switch looks identical although it is not Honeywell. It is an unfamiliar Chinese mfg. The wire connections and tube are in the same position, with the wires being is series with the auger feed. I will watch the display for stove status before the alarm. From what you are saying I am guessing their is a parameter that will allow me to monitor the exhaust motor speed. When I do get the alarm #8 no depression alarm, the auger shuts down but the exhaust fan continues to run. It seems to be looking for a correction to start feeding again. I end up having to shut the stove down manually.


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## Monica in France (Jan 18, 2018)

<<
The N.C. contact allows the pellet auger to start immediately to fill the burn pot.
The exhaust/combustion fan then starts.
The vacuum switch contact then opens, and at this time the logic sends power to the auger via the common wire at the control board.

Are you sure of this ?
My RDS manual states that after the igniter is pre-heated ,  the exhaust fan comes  on and the auger fills the burn pot with pellets.
Mine certainly follows this algorithm.
That way you save a lot of complications. Both in the hardware and the software.

After any alarm situation the stove goes into closedown mode , the ventilator goes at full tilt until the stove is at a temperature where one can be certain there are no combustion fumes. It then stops.
In your case the ventilator going full tilt could remove the alarm situation thus causing the firmware to  get  its nickers in a twist.?

My menu has a 'Display Status' entry.
It displays the flue temperature , exhaust fan revs , and if the the auger motor is on or off.
The words 'display status' are my translation of the French displayed on my sceren. Ravelli's  english translation could well be different !


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## Manly (Jan 18, 2018)

Monica in France said:


> <<
> The N.C. contact allows the pellet auger to start immediately to fill the burn pot.
> The exhaust/combustion fan then starts.
> The vacuum switch contact then opens, and at this time the logic sends power to the auger via the common wire at the control board.
> ...



I just downloaded a RDS manual that has a block diagram of the logic sequence. It is not for my specific year Francesca but hopefully is similar. The start/run sequence I previously described was from my observations only. As soon as I get time I will give this stove one final go through; clean the MAF sensor, observe the exhaust fan speed prior to alarm, and if it still continues to alarm, I will retire the stove for the time being. Thank you for your continued input.  Jim


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## Manly (Jan 20, 2018)

Monica in France said:


> <<
> The N.C. contact allows the pellet auger to start immediately to fill the burn pot.
> The exhaust/combustion fan then starts.
> The vacuum switch contact then opens, and at this time the logic sends power to the auger via the common wire at the control board.
> ...



So I removed and cleaned the MAF sensor in the intake pipe. I monitored the combustion fan as it cycled through. The rpm or whatever unit the fan is measured in stayed consistent. It was around 1680 initially, came down to 1322 during flame light, and stayed around 1327 during work stage when I got the alarm #8 depression about 1 minuet after the heat blower fan came on. This trips at the same time each time I try. Does anyone know if there are any points on the control board that can be jumped to help isolate if the MAF is defective? Possibly put a resistor in its place for test purposes. I can not understand how this unit can get all the way to the work stage with good air flow and flame then just go into alarm. If I am at the point where I have to change out the control board, it just isn't worth it.


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## Pelleting In NJ (Jan 20, 2018)

Since you have an airflow / MAF sensor ("Debimeter" in Ravelli speak) in the intake tube, you do have the later RDS Francesca model. My guess is that you need to replace the MAF sensor. I bet that the control board only looks at the MAF airflow signal after it exits the ignition phase, and goes into the "work" phase of operation. Then it sees a lower-than-expected airflow signal, which trips the Low Draft alarm. The airflow is either actually too low, or the MAF sensor is defective (outputing a falsely lower signal than it should, for a given amount of actual airflow).

Read thru the below thread.

https://www.hearth.com/talk/threads/ravelli-francesca-pellet-stove.164499/

The MAF is actually a simple device, a U shaped board, with a heater resistor R1  next to a thermistor RT1. The other side of the U has an identical thermistor RT2. I bet these MAF units go bad because the two matched thermistors drift apart in value (Ohms versus temperature.)  Or the 750 Ohm heater resistor opens. Any of these 3 parts could be easily replaced to repair the MAF. The difficulty is finding the correct part number of the thermistors, but a simple experiment with a good MAF could determine the characteristics so that we would know how to repair future owners problems with the MAF sensor.

https://www.google.com/search?q=rav...biw=1745&bih=849&dpr=1.1#imgrc=-PgKSCXWweAXhM:

A typical thermistor costs about 10 cents each...
https://www.digikey.com/product-detail/en/tdk-corporation/NTCG103JF103FT1/445-2550-1-ND/934249


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## Manly (Jan 20, 2018)

Monica in France said:


> My stove is the generation before yours but it is visually very similar.
> I post a picture of my depression sensor. made by Honeywell.
> You can see the connections well enough to see if yours are the same.
> But please , no comments on all the pellets that need vacuuming up !
> ...



Upon taking a closer look at the photo of your depression sensor, It looks identical to the original switch I removed from my stove, although mine has a different brand name label. Most likely made in the same factory with different label. Anyway, going under the assumption they are the same, it would appear that your switch has the flow tube attached to the H high pressure side. If that is correct, then I installed my new switch with the hose on the wrong side. If that is so, then I have been under the wrong impression as to how the "logic" of this safety device works. I thought it looked for a vacuum, or negative pressure and if a blockage occurred the switch would transfer contacts and send voltage back to the control board to go into alarm. By putting the hose on the pressure side, the contact on the switch remains closed, the auger keeps running, I don't get an alarm and the stove runs fine at this time. If this is the correct operation, then I would guess a blockage in the exhaust or flue would cause the fan to create positive pressure, open the contact to drop out the auger and give a depression alarm. This is where I am at now and the stove appears to be running fine.  In summary, I believe, or am guessing, my original alarm #13 drought insufficient may have been caused by a dirty MAF sensor, which did have a visible coating of dirt, as well as my flue T being about 1/2 full of soot. Once I decided to change the vacuum switch, which I determined to be defective using presumably incorrect understanding of operation, I installed the hose on the wrong side which has caused me much consternation. Let me know if you agree with my final connections. Hopefully I am running in the proper manner. I would like to thank you and everyone who contributed input to help resolve my issue. If everything continues to run well, I would say cleaning was the ultimate fix.   Regards,   Jim


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## Manly (Jan 20, 2018)

Pelleting In NJ said:


> Since you have an airflow / MAF sensor ("Debimeter" in Ravelli speak) in the intake tube, you do have the later RDS Francesca model. My guess is that you need to replace the MAF sensor. I bet that the control board only looks at the MAF airflow signal after it exits the ignition phase, and goes into the "work" phase of operation. Then it sees a lower-than-expected airflow signal, which trips the Low Draft alarm. The airflow is either actually low, or the MAF sensor is defective (outputing a falsely lower signal than it should, for a given amount of actual airflow).
> 
> Read thru the below thread.
> 
> ...



Please take a look at the post I made prior to your reading your post and see if you agree with my finding and current situation. I would like to verify that I have my vacuum switch now correctly installed. Greatly appreciated,   Jim


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## Pelleting In NJ (Jan 20, 2018)

https://www.hearth.com/talk/attachments/p1000921-jpg.53207/

See pic above, my pressure switch, on my non-RDS Elena model, is installed just like "Monica in France", with the rubber hose on the right side "H" switch nipple, and the electrical connections to the outer two (NC & C) switch terminals (the NO terminal tab nearest the switch body is not connected to a wire). This works because the other end of the hose connects to the output side of the exhaust blower. Most other stoves have a vacuum switch that connects to the intake side of the exhaust blower.

I agree with you, the switch is really to detect positive pressure if the external flue pipe gets blocked, which then opens the switch, cutting off the auger and setting an alarm.


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## Manly (Jan 20, 2018)

Pelleting In NJ said:


> https://www.hearth.com/talk/attachments/p1000921-jpg.53207/
> 
> See pic above, my pressure switch, on my non-RDS Elena model, is installed just like "Monica in France", with the rubber hose on the right side switch nipple, and the electrical connections to the outer two switch terminals (the terminal tab nearest the switch body is not connected to a wire). This works because the other end of the hose connects to the output side of the exhaust blower. Most other stoves have a vacuum switch that connects to the intake side of the exhaust blower.
> 
> I agree with you, the switch is really to detect positive pressure if the external flue pipe gets blocked, which then opens the switch, cutting off the auger and setting an alarm.



Thanks.


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## Monica in France (Jan 21, 2018)

"Manly" said <
 If that is so, then I have been under the wrong impression as to how the "logic" of this safety device works.
 I thought it looked for a vacuum, or negative pressure and if a blockage occurred the switch would transfer contacts
 and send voltage back to the control board to go into alarm.
By putting the hose on the pressure side, the contact on the switch remains closed, the auger keeps running,....
>
The manual says
<  The VACUUM SWITCH is an electromechanical safety device that garantees the smoke duct is always free. It works by depression. >

"Manly" has actually connected his "electromechanical safety device" to an ohm meter  and sucked. Could he confirm his statement please.
If he is right , it sucks as a safety device  . But I know from bitter experience how easy it is to get muddled up with these things.
What with a choice of sucking and blowing , two nipples and three contacts.   I managed to scrap a working parking brake motor recently because my test lead was duff.

"Pelleting in NJ" :  what a beautifully clean stove you have. I wish I had your discipline.
But I notice the tip of the thermocouple just visible and not poked right through the hole as I do ( I forgot to note how it was originally ).
Is your way "better" or is it not important ?
I have absolutely no knowledge or experience on this subject and enquire to have more knowledge and possibly avoid a bad experience.


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## Ssyko (Jan 21, 2018)

Ahhhhh ok i see it now. The switch is working on the pressure side the connection for the hose is on exhaust (pressure)side of the combustion blower instead of the  intake (vacuum).


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## Manly (Jan 21, 2018)

Ssyko said:


> Ahhhhh ok i see it now. The switch is working on the pressure side the connection for the hose is on exhaust (pressure)side of the combustion blower instead of the  intake (vacuum).



I had been going under the false assumption that the pressure switch was looking for vacuum to operate the contacts properly. The switch tube is under a vacuum state when the stove is operating. Therefore if the tube is connected to the Lo, or vacuum side, the electrical contacts open as soon as the exhaust fan starts and the auger shuts down as soon as the stove goes into the work mode. I have tested the operation of the switch and contacts extensively trying to determine the operational sequence of this stove, since I had no decent descriptive documentation. If I had marked my original switch as to where the hose came off I could have saved a lot of time. The pictures posted by Monica in France and Pelleting in NJ confirm this is the proper connection; air tube on the H nipple and wires on the NC terminals. All that being said, If I were designing a safety circuit, this would not pass muster. It is not intrinsically fail safe. In the machine controls field control devices that fail or become disconnected should create a fault condition. Not here. Enough said, the stove has been running all night. .


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## Ssyko (Jan 21, 2018)

Cool, glad your back in the heat!


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## Pelleting In NJ (Jan 21, 2018)

Monica in France : The picture of my stove was taken when the stove was new...that is why it is so clean. Concerning the thermocouple, it should be inserted into the orange seal so that a small portion of the smooth metal barrel is still visible from the outside. If you push it in any further, until the braided wire is inside the orange seal, that is too far, as the seal will not be airtight around the braid.

Manly : Although the Ecoteck/Ravelli technical manual calls this a "Vacuum" switch, that operates on "depression", that is not actually (as we see) how the stove is designed. I think the translation from Italian may have botched-up the switch description a bit.

Concerning fail-safe design, these stoves are no less safe compared to any other stove which senses vacuum on the intake side of the exhaust fan, which close a contact when vacuum is present. These "vacuum" side stoves can't detect if the external flue pipe is blocked, as this condition will still keep vacuum pressure on the switch, keeping the contacts closed, which will allow continued stove operation. In addition, the Ecoteck/Ravelli stoves monitor the RPM of the exhaust fan, and if the fan is running too slow, or not at all, the stove sets an alarm and shuts down. Compared to a typical "vacuum" switch stove, the Ecoteck/Ravelli stoves actually have more safety features.


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## Monica in France (Jan 22, 2018)

'Pelleting in NJ':
I am in denial.
I ( perhaps like the Ravelli translator ) was completely convinced that the switch worked on vacuum.
It is so obvious that it should.
The 'pressure' outlet on the fan housing on my stove even looks moulded for a venuri effect. ( or did I imagine that ? )
So next time I stop the stove to clean it I will not only ensure that my thermocouple conforms with your specification ,
 but I will myself connect an ohmmeter to that switch and suck. That way I will dispell any lingering doubts I have.
Not that my name is Thomas but ....

And your other point is perfectly valid , even if back pressure in the flue does not stop the auger straight away ,
it will ensure the exhaust fan works overtime to resist it which is in some ways a better solution.


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## Monica in France (Jan 25, 2018)

It was cleaning time this morning , so I pulled off the side panel and got down on my knees and investigated that 'vacuum' switch.
I can confirm  , as stated by 'Manly' and seconded by 'pelleting in NJ' , that this not a fail-safe vacuum device.
It will disconnect the auger motor if the pressure at the base of the flue builds up.

In the 'status' menu you can turn the auger motor on and off , ( this is useful to prime the screw ) ,
and there is no reason for the exhaust fan to come on , after all the switch is 'normally ' closed.
But it does. 
Maybe it started life configured as fail safe until they realized it didn't really matter.


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## liquidwood (Dec 28, 2019)

Hello all...

I am having issues with my Ravelli Francesca stove which looks like the one in this post.

Can anyone tell me what model stove A, B (etc) I have based on the pics I sent (I think the mfg date is 2011 or 2012)

Does anyone have the manual, programming guide and schematics for this stove? Thank you in advance for any help.


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## Pelleting In NJ (Jan 1, 2020)

Liquidwood
Send me your email address through the messaging feature of this forum, and I can email you some technical info on your stove.


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