Harman Absolute not shutting down, causing pellet fire in ash bin.

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whalefish

Member
Jan 26, 2022
15
Oregon
I've got a 3 year old Harman Absolute43 pellet stove that's been acting up this winter with a number of issues, but most urgent is the recent spate of ash bin fires. The stove is set to it's thermostat, but once it hits the desired temp, the auger continues to feed pellets into the firebox, overheating the place and eventually spilling flaming pellets into the bin, which pile up and burn like crazy. The fan eventually shuts off, and smoke starts to leak into the house while the bin smolders...Any ideas? Everything was cleaned 3 weeks ago, including the exhaust sensor.
 
Have never worked on a touch screen Harman,but the burn system is the same, sounds like your exhaust probe is "wigging out".
 
Has the stove been totally cleaned from the door glass to the termination cap outside? Stove is not sensing temp correctly from either a bad esp like Bob said, a glitch in software, or a dirty stove,pipe ect. I would start with a full cleaning along with unplugging the stove and reboot.
 
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Is there a software update for these stoves?
 
Thanks for the replies, I'll look into a software update, it does seem like a glitch of some kind. I did a very thorough cleaning but did not clean the entire stove pipe, as it runs up our chimney 30ft. It's also around 12" diameter so I doubt there is much of an obstruction. The exhaust probe displays what seems to be an accurate temperature reading on the touch screen. If there is something wrong with it, it typically displays a sensor error.

I should add that we've had a number of power outages recently so it's had ample opportunities for a reboot.
 
Using a power surge protector? Also you say it 12”, so does your venting just go into a chimney with no liner?
 
You really should get a good UPS battery backup. Power outages, especially quick out then back on can damage electronics with the surge as the power kicks back on.

sam
 
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You really should get a good UPS battery backup. Power outages, especially quick out then back on can damage electronics with the surge as the power kicks back on.

sam
Or if not a UPS battery backup at least a good quality surge suppressor.

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Thanks for the suggestions, could the power outages have caused this kind of behavior with the stove, like a faulty control board?
 
It seems you have multiple issues, one of which is a Harman Absolute defect that Harman simply can't and/or refuses to appropriately address and one of which can be addressed to an extent:

1) Feeding despite already at set temperature is an embarrassment to the Harman brand which I addressed in this post: https://www.hearth.com/talk/threads/harman-absolute-63-do-not-buy.190098/

You'll find that there have been more and more complaints about this issue (on Hearth.com and other forums) and a lot of the old Harman guys on this board believe Harman can do no wrong and that it's just a cleaning issue. I promise you that this issue is nothing you can address with cleaning as I've had this stove for 5 years, know it inside and out and just have to live with this issue. It's mostly just an issue during shoulder seasons but it's an issue nonetheless.

2) If the pellets are falling into the ashpan, you have a feed rate air flow issue. The default feed rate is 65% which is probably too high for the pellets you are using. Try cutting it to 50% or lower to see if that helps. The pellets will also cook faster if you address the airflow issue. The two most important things you can do for this with the Absolute is to poke all the burn pot holes with an allen wrench (or something similar) and to open the igniter opening below the burn pot and clean out the ash.
 
"You'll find that there have been more and more complaints about this issue (on Hearth.com and other forums)"
Huh? Proof?
"a lot of the old Harman guys on this board believe Harman can do no wrong"
Proof?
What has Harman said and done about your problem and what parts have you replace to fix it? Surely it is fixed, you would never own a car that never shuts off, idles until it runs out of fuel.
 
"You'll find that there have been more and more complaints about this issue (on Hearth.com and other forums)"
Huh? Proof?
"a lot of the old Harman guys on this board believe Harman can do no wrong"
Proof?
What has Harman said and done about your problem and what parts have you replace to fix it? Surely it is fixed, you would never own a car that never shuts off, idles until it runs out of fuel.

You'll find this issue all over the Pellet Stove and Harman Facebook groups which are more active than this website.

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You honestly want proof that the consensus on this board is that Harman can do no wrong? Really? Your response proves my point.

Harman stopped responding to my requests to address and then a month later issued a software release that was geared to address the issue but it doesn't fix it.

Your car analogy is off. Your car does not continually run for 4 months a year, the stove does. As I said, this is really only an issue (for me, with an appropriately sized stove) during the shoulder seasons.
 
I don't understand your response. I get that you are looking for support from the Harmanheads but you asked for examples and I provided them. I'm sorry your attempt to shut down a legitimate complaint about Harman was not successful but maybe be better?
 
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Ok let's not hijack the thread with squabbling. So I've run the software update and the problem continues. I did dial back the feed rate and it isn't dumping flaming pellets into the bin anymore, but it will continue to feed long after it's hit the thermostat temperature. It automatically dials back the feed limit to 10% at this point (I've set the max at 40%), but occasionally will stay stuck at 10%. If I'm not on top of it, it'll hit 80 degrees F in no time. Seems like a control board/electronics glitch to me.
 
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Another update, the issue seems to have gone away for now. Not sure what was wrong. It's been about a week now with consistent operation. Hoping this holds out and I don't have to replace the control board.
 
Is the logic in the touch control or the circuit board down on the side? I have not had to troubleshoot these yet. The only thing I have done is replace the communication cord. It broke from where it got continuously bent opening and closing the hopper lid
 
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Is the logic in the touch control or the circuit board down on the side? I have not had to troubleshoot these yet. The only thing I have done is replace the communication cord. It broke from where it got continuously bent opening and closing the hopper lid
I would assume it's related to the control board on the right side. When your cord needed replacing, was there an error message or did you have to troubleshoot?
 
The touch control went blank. With a Mirror I could see the wire was visibly wore and cracked right where it bends with the lid hinge. By the way it is just a black ethernet cable.
 
Something I have wondered about. As Harman's with TC are set up for using a wireless temp sensor, and the "stays running" issue seems to be sporadic and not very common, what about RF interference or even EM interference. Food for thought.
 
We are currently having the same issue with our Absolute 63, which is a little over 3 years old. Power flickered on Saturday and ever since it will not shut down when it reaches temp (via wireless sensor that is communicating with the control panel). It doesn't even shut down when we turn the power off, just says "shutting down" forever. Even if we unplug it and plug it back in it will still say "shutting down". We have to physically open the hopper to get it to stop running. We do not have a surge protector on the unit at all, but after all this we will. We have updated the firmware as well.

We have not changed any settings in the 3 years we have owned it. Just have it on a schedule and clean it/empty it when it is needed.

Any suggestions? Is yours still working properly?