Austroflamm Air Sensor or Logic Lock?

[Jeff Lawson]

Hey everyone:

I recently purchased a used Austroflamm Integra. I gave it a thorough cleaning, and yes, by this boards standards . It has run well for about 6-8 bags or so. I ran these pellets without an OAK.

This weekend I installed an OAK, and when I went to fire the stove last night, it burns normally for about 10 minutes or so. But then the combustion blower slows down and the flame gets lazy and smokey. Pellets continue to feed at the same rate during the combustion blower slowdown.

Tonight, I cleaned my air intake sensor with QD Electronic cleaner. I disconnected the OAK, as this was the only change since last operating properly. Then I fired the stove. But it behaves the same.

When I open the door, the air does not seem to increase and pellets continue to feed. smwilliamson posted this 11 step combustion fan troubleshooting process last year on another thread, and I seem to be failing step 9.

So is the next step to purchase a new air intake sensor? Any other tricks before I find and order a sensor? I feel because it was working one day...and then so suddenly not working...it seems typical electrical.

Thanks in advance for your help.

 

[Mark_ms]

welcome to the boards.
Is this an insert or freestanding?
What kind of voltages were you getting in the combustion motor test?
Here is a copy of the Integra manual in case you don't have one.

 

[Jeff Lawson]

Thanks! I'm glad to be able to tap into the knowledge and hopefully pay some forward. It seems like a great community.

It is free standing. I didn't check the voltage because the combustion motor starts strong during start up...so I guess I was thinking it was more of a wouldn't situation than a couldn't situation. Let me know if I do need to test those voltages.

Thanks for this manual. I did get the original Owners manual, but what you attached is much more technical and going to be very useful.

 

[Jeff Lawson]

Here's maybe a little more info that may help to tell you. I just thought I would give it a try again as we are in the middle of this arctic blast.

It burned for a little longer this time before getting sooty and dirty, but eventually I again had to just shut it off. But the weird part is both fans were still running long after the stove was cool. So I just unplugged it.

 

[Mark_ms]

Lets back up a bit.
You say you cleaned it thouroughly,
Pulled inspection port on right hand side and Vacuumed?.(just below circuit board)
Pulled cast iron grates and vac/scraped the exchange tubes and opened up holes on bottom between tubes? holes also visible in the combustion chamber from the bottom
Pulled convection blower and cleaned?
Pulled combustion blower and the blower housing cleaned and replaced gasket?
Put new gasket on lower cast wall (inside)?
Does you air sensor have a gasket??
When you installed the OAK did you unplug the unit??
As you probably read in these forums 80% of problems lie in a dirty stove so...just checking.

 

[Mark_ms]

We overlapped abit here, I think your control board is shot

 

[skibumm100]

I would also make sure the ribbon cable is plugged into the air flow sensor card correctly and those contacts are clean and pins are not bent. Since the combustion blower does not speed up when you open the door, the stove doesn't know it has lost air flow past the sensor. That doesn't explain the part about the fans staying running long after the stove is cool. Just how long is "long after"? Mine will run for "a while" after I shut off the switch and the low temp switch has changed state. You might try unplugging the stove and letting it sit for an hour and try plugging it back in and trying it again. I have read some posts about the stove having its "brain scrambled" and unplugging it and plugging it back in helped. I have no experience with this phenomenon and it may be urban legend. I would try everything I could try before shelling out money for a new main board. Don't forget that this board can be repaired for less than a new board, most likely.

Mark has way more experience than I do with this stove but I'm just throwing a couple of things to try out there. I am by no means an expert on Austroflamm's. Maybe I will be next year....

 

[Mark_ms]

skibumm that is a pretty good thought (it was after all 2am when I posted ) my combustion fan will run up to 30 minutes after I turn it off, convection about the same time.
Jeff before you plug it back in make your air flow sensor is plugged in properly and snugged down against the gasket.

 

[Jeff Lawson]

Lets back up a bit.
You say you cleaned it thouroughly,
Pulled inspection port on right hand side and Vacuumed?.(just below circuit board)
Pulled cast iron grates and vac/scraped the exchange tubes and opened up holes on bottom between tubes? holes also visible in the combustion chamber from the bottom
Pulled convection blower and cleaned?
Pulled combustion blower and the blower housing cleaned and replaced gasket?
Put new gasket on lower cast wall (inside)?
Does you air sensor have a gasket??
When you installed the OAK did you unplug the unit??
As you probably read in these forums 80% of problems lie in a dirty stove so...just checking.

Yes on all this except removing the combustion and convection fans. I wanted to get it running initially to make sure I had enough confidence it was worth installing. I understand what you are thinking, so I will tear into those and clean it again to rule that out. Believe me, I hear you on the cleaning so I'm going to get to those fans and tear down again. I need to rule out everything I can.

The troubling part for me is that it's not like I haven't had it running good, it has ran great so far. And it's not really a performance thing that dwindled over time. It has really been an off the cliff type of change.

I did not unplug the unit to install the OAK. So I'm not sure about that.

 

[Jeff Lawson]

I would also make sure the ribbon cable is plugged into the air flow sensor card correctly and those contacts are clean and pins are not bent. Since the combustion blower does not speed up when you open the door, the stove doesn't know it has lost air flow past the sensor. That doesn't explain the part about the fans staying running long after the stove is cool. Just how long is "long after"? Mine will run for "a while" after I shut off the switch and the low temp switch has changed state. You might try unplugging the stove and letting it sit for an hour and try plugging it back in and trying it again. I have read some posts about the stove having its "brain scrambled" and unplugging it and plugging it back in helped. I have no experience with this phenomenon and it may be urban legend. I would try everything I could try before shelling out money for a new main board. Don't forget that this board can be repaired for less than a new board, most likely.

Mark has way more experience than I do with this stove but I'm just throwing a couple of things to try out there. I am by no means an expert on Austroflamm's. Maybe I will be next year....

Yes, the ribbon is plugged in good. It probably ran for say 45 minutes after turning it off. But the stove was completely cool to the touch.

I don't know about the stove...but my brain is certainly getting a good scramble.

Jeff

 

[skibumm100]

The stoves runs for a time period determined by the main card. Mine runs a long time so after a test burn with mine in the driveway, I make sure the fire is out and go have a beer in the house by the other pellet stove and come back later. By then it's not running (I drink slow). It may be 30 minutes after the switch is shut off or 30 nminutes after the low limit switch changes state, I'm not sure and don't have my manual in front of me.

 

[Mt Bob]

Yes,these stoves can get "logic lockup",have had it happen to mine several times over the years,also experienced it on chevys and fords with their early computors.Unplug for 30 min. plug back in and try.If any fan starts with switch off,unplug low temp. switch and see what happens.You probably will have to send board out for repairs.I do have copy of diagnostic manual,could email it to you,but I found it on the net.Bob

 

[Jeff Lawson]

Yes,these stoves can get "logic lockup",have had it happen to mine several times over the years,also experienced it on chevys and fords with their early computors.Unplug for 30 min. plug back in and try.If any fan starts with switch off,unplug low temp. switch and see what happens.You probably will have to send board out for repairs.I do have copy of diagnostic manual,could email it to you,but I found it on the net.Bob

Thanks Bob! I unplugged it, but only for 20-30 seconds or so. So I will have the wife unplug and by the time I get home it will have a good reset.

Mark_ms posted a link to a manual in the second post, but if you have something different, by all means the more information the better. Especially on these "legacy" stoves.

 

[RKBAGUY]

Just by way of a few suggestions:

1) Turn stove off, allow to cool. Unplug stove. Remove burn pot and ash tray, clean, and be sure to vacuum underneath burn pot.
2) Remove the airflow sensor, and carefully set it aside. Put a vacuum nozzle to the air intake at the back of the stove to be sure there is a free and open air path. I actually had a handful of unburned pellets in the pipe between the bottom of the pot and the opening at the back, restricting the airflow.
3) Before replacing the airflow sensor, spray it with electronics/contact cleaner from Radio Shack, or equivalent. Replace, being sure to not touch the sensor. Replace OAK connection when done.
4) Plug stove back in and begin restart procedure, or go through the diagnostics - your call. In the span of time it takes to complete these steps, if there's a 'logic lock', it will have been purged.

Let us know what happens!

 

[Jeff Lawson]

Well boys....the winners are bob bare and RKBAGUY ! I had already done steps 1-3 RKBAGUY posted...but it seems it was logic locked. I came home from class tonight, plugged it in, and it has been toasty since! We'll see how it goes from here long term, but tonight its warm...

Sincere thanks to everyone!!

Jeff

 

[skibumm100]

Glad it's working the way it should. I guess it's not urban legend. File that one away in the memory for the next time.

 

[Jeff Lawson]

Still warm tonight. Very happy. The wife is digging all the toilet paper streamers I have hanging all over the place.

I would still like to increase the combustion air a bit. What is the best way to do this? Stove in operation...on the fly? Shut down and unplugged? I may see if I can take a little video and post up to see what you all think. The burn pot is full up to the big air holes.

 

[Jeff Lawson]

Okay...if you don't mind grading my burn. These are box store pellets from Show Low, AZ. I'm on the fence to either leave it or increase the combustion air slightly. Curious for opinions.

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[Mark_ms]

Flame looks "ok" what setting is at?
what is that noise in the background?
I would clean the combustion fan and convection fan before doing anything else (unplugged), as you said you had not done that

 

[Jeff Lawson]

Flame looks "ok" what setting is at?
what is that noise in the background?
I would clean the combustion fan and convection fan before doing anything else (unplugged), as you said you had not done that

I'm not sure what setting it is currently. I will post back when I know.

That noise is the convection fan. I plan to remove, clean, and install new bushings.

Probably good advice. I think when the weather warms up, I will do another cleaning including the fans this time.

 

[Mark_ms]

Yeah that fan is very noisy, you should just barely hear it.
When you order the bushing order the gasket for the combustion fan too.

 

[Jeff Lawson]

Yeah that fan is very noisy, you should just barely hear it.
When you order the bushing order the gasket for the combustion fan too.

Good call. Any idea how many cleanings that gasket will last for? Is it the same asbestos-like material the lower cast wall gasket is made from?

 

[Mark_ms]

you replace the gasket everytime you pull the combustion blower. It is not made of the same material as the inner wall gasket, more fiberous. Some folks on here buy gasket material by the sheet and cut as needed like Lytherm or similar.
You will improve your airflow considerably by making sure both fans are clean. You should do a complete cleaning about every ton burned.

 

[RKBAGUY]

Agreed, that fan noise is terrible. I thought my little 'ticking' was bad, but that's off the hook.

Regarding the bushing, be sure you get the right one. There seem to be two different styles. I ordered one from Jason Munson (Energy Parts Plus) and the one I got doesn't fit my housing. It's too big in diameter and lacks the four 'prongs' on the rubber to fit into the slots on the housing. I'll try to post a couple photos later, if it doesn't slip my mind.

Regarding the speed of the combustion burner, it all depends on which model Integra you have. The earlier versions with the non-digital "dial" type user board have one hole in the face plate that gives access to the combustion burner potentiometer, which will adjust speed +/- 25% (clockwise is faster, counterclock is slower), the one located on the rear of the board is for the auger speed and it also operates at the same 25% range.

For my needs, I turned the combustion fan all the way up, and the auger pot all the way down, preferring to use the main dial to adjust the pellet rate. With those pot settings and the main dial all the way down, the stove will go out from lack of pellets, but if I turn it up to right around the first marked line (roughly 9:00) it was enough to prevent the stove from going out. I find it more efficient to maximize air movement through the stove and more fully burn whatever pellets are in the burn pot while having the fans at a higher rate and adjust more conveniently with the main dial.

 

[skibumm100]

I was gonna ask you how much noise your auger motor makes but you probably can't hear it over the convection fan. FYI, my convection fan is very quite but my auger motor makes some electric motor noise, I took the gearbox apart and rearranged the grease inside so it was on the gear teeth instead of just packed around the teeth. I can't say it improved so I may try a different auger motor. My York insert auger makes almost no noise.