# harman combustion fan won't shut off?



## ivanhoe (Apr 28, 2013)

My Accentra combustion fan won't eventually shut off after initiating shut down mode. It goes into shut down but the combustion fan runs & runs. It use to shut off after awhile but not no more, what gives? Now i can't do a shut down in the morning and go to work and come home with a off stove but one with the combustion fan still running. Could it be the ESP is starting to act-up?


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## DAKSY (Apr 28, 2013)

ivanhoe said:


> My Accentra combustion fan won't eventually shut off after initiating shut down mode. It goes into shut down but the combustion fan runs & runs. It use to shut off after awhile but not no more, what gives? Now i can't do a shut down in the morning and go to work and come home with a off stove but one with the combustion fan still running. Could it be the ESP is starting to act-up?


 
Sure could. Have you pulled it & cleaned it? If it doesn't sense the temperature drop in the exhaust stream, it'll keep on keepin on...


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## Don2222 (Apr 28, 2013)

Hello

Clean the ESP probe real good and unplug it from the circuit board and plug it back in to assure a good connection. Be careful not to break the plastic clip that holds it in.


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## ivanhoe (Apr 28, 2013)

Thank you, I will pull it out & clean it good. I never pulled it out before but always gave it a brush-over when doing a cleaning of the stove.


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## DAKSY (Apr 28, 2013)

ivanhoe said:


> Thank you, I will pull it out & clean it good. I never pulled it out before but always gave it a brush-over when doing a cleaning of the stove.


 
You really should pull the ESP every time you run a brush through the internal vent in the stove.
That's a VERY sensitive part & the slightest bend to the sheathing will render it suspect, or worthless...
A 1/4" magnetic nut driver is the ideal tool for the job of pulling the zip screw that holds it in place. 
Speedy White glass cleaner from Rutland works really well for cleaning the ESP.


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## ivanhoe (Apr 28, 2013)

Finished cleaning it! As soon i plug it in, the combustion fan comes on even when in OFF position. It works when the flame is started, meaning it waits for temperature to rise before starting to feed pellets! It looks like it works on the high end of the parameter but not the low end of it!?!? Poor design when the OAK is attached, have to remove the piping to be able to pull the ESP probe out! Harman tech take note if you're chiming in!!


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## JRegs1 (Sep 17, 2018)

I'm having the same issue. Did you ever get it working as expected?


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## ivanhoe (Sep 28, 2018)

I did replace the ESP probe but it has being a while. If I remember correctly I replaced the circuit board and the problem went away.


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## Don2222 (Sep 29, 2018)

ivanhoe said:


> I did replace the ESP probe but it has being a while. If I remember correctly I replaced the circuit board and the problem went away.


X2 - It is the Circuit Board.
I like the new Rev F Circuit Board, it has a better heat algorithm and it finally has the vacuum error 2 blinks so No More guess work when there is a vacuum problem!


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## JRegs1 (Nov 6, 2018)

I've exhausted all resources and wanted to know why my Harman Accentra Pellet Insert's combustion fan wont automatically turn off and continues to run indefinitely. The only way it turns off is to open the door or unplug. Here are some things I've done and noticed:


Removed and cleaned the combustion motor & fins. (Found a quarter size piece of Styrofoam in motor mount air passage/exhaust area).

Cleaned feeder chamber.
Removed and cleaned ESP Probe with green scrub (Found a dent in probe & is slightly bent)







While ESP Probe was removed, cleaned exhaust area.
Followed wiring for ESP Probe back to control board & looks good.

The connector on the control board for the ESP Probe  pulled right off of the 2 pins. Tried leaving it off, still failed.






Cleaned compass panel and heat exchange area.

Burn pot and distribution blower cleaned.


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## rickwai (Nov 6, 2018)

With damage to esp I would bet it is esp if the rest of the stove and piping is clean. It could be the board also. I typically replace esp when I replace a board regardless. That way you start w/ all fresh controls.


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## sandpipe (Nov 7, 2018)

Original poster-- did you always keep your stove plugged into a good surge suppressor to prevent damage to the circuit board?


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## ivanhoe (Nov 7, 2018)

sandpipe said:


> Original poster-- did you always keep your stove plugged into a good surge suppressor to prevent damage to the circuit board?


Always, haven't any issues since the board replacement.


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## JRegs1 (Nov 9, 2018)

rickwai said:


> With damage to esp I would bet it is esp if the rest of the stove and piping is clean. It could be the board also. I typically replace esp when I replace a board regardless. That way you start w/ all fresh controls.


I was told that this is expected behavior for the Accentra Insert in the fall because it's not cold enough outside. The stove will constantly stay 5 degrees above shut off temperature. Apparently I need to buy a new board which now comes with a timer on it.


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## JRegs1 (Jan 18, 2019)

This is still an issue. My Harman Accentra Pellet Insert combustion blower wont automatically turn off and continues to run indefinitely. The only way it turns off is to open the door or unplug. It has been thoroughly cleaned, no status lights blinking. I've been told by Harman there is a new control board replacement part 1-00-05886, superseded control board 3-20-05374 and comes with a timer which will force the combustion blower to shut off if the ESP probe does not.

My dealer thinks its a draft problem because when I open the door, the combustion blower shuts off. Its a 4" into 6" liner. Does anyone know if this could be a draft problem?


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## Don2222 (Jan 18, 2019)

It is usually a bad circuit board that will cause that.


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