First post. Harman p35 stopped working. Won’t feed pellets, but status light is off and combustion blower light stays on. Loud buzzing

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schmobodia

New Member
Nov 13, 2022
8
N Am
Coldest day of the year! The stove was working fine yesterday. Here’s what my panel looks like in test mode:

[Hearth.com] First post.  Harman p35 stopped working.  Won’t feed pellets, but status light is off and combustion blower light stays on.  Loud buzzing
So the feed motor definitely isn’t doing anything.

And if I turn all the controls off, the combustion blower light stays on. Doesn’t appear to be blowing at all, and has a loud buzzing sound.

I checked the feed spot of obstructions, but it looks fine?
 
Unplug the stove, remove the ash pan and the combustion blower cover. Clean around and behind the fan blade. Spin the combustion blower fan by hand and see if it turns freely. If it's tight or "jerky" feeling it's bad. When you have the cover off take a flashlight and look into the exhaust port make sure it's clear. You should also be able to see the ESP probe make sure it's clean. After re-reading your post you have a no feed issue too. A lot of stuff happening all at once makes me think it's a bad board. Power surges of any kind are really bad for these boards.
 
From where in the stove?
How old is the stove?
when was it cleaned (complete) last
Welcome to the forum
A bit hard to pin point the noise. Adding a video:
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We’ve been in the house for a year, so I’m not sure the date of install.

I had it serviced last year, and I did the work myself this year. Fines are cleaned out. It’s been working fine for a month, but yesterday was the first day using it fully all day.

Are there any fuses to check? The noise makes me thing of a stuck motor, so perhaps the auger motor is dead, or a bearing seized?
 
Unplug the stove, remove the ash pan and the combustion blower cover. Clean around and behind the fan blade. Spin the combustion blower fan by hand and see if it turns freely. If it's tight or "jerky" feeling it's bad. When you have the cover off take a flashlight and look into the exhaust port make sure it's clear. You should also be able to see the ESP probe make sure it's clean. After re-reading your post you have a no feed issue too. A lot of stuff happening all at once makes me think it's a bad board. Power surges of any kind are really bad for these boards.

I did notice yesterday getting a status blink related to the temp prob. But we rarely use it in “auto” mode. And it went away after a while.

Is there a way to manually progress / reverse the auger? Or to confirm if the issue is with the auger motor?

And the status light, I *think* I remember it being on solid when everything is working? Or is it default off?
 
Default is solid on, on my PC45. A loose connection on your room temp probe on the back of the stove will stop the auger from feeding for sure in room temp mode but I'm not sure if it will affect the auger in stove temp (constant burn) mode. I don't have any experience with inserts but I'm sure others do and will be along shortly.
 
To me sounds like the Combustion fan is stuck
Way too loud for an auger motor and they cycle not stay on
Try what Northwoodneil said to do
 
I couldn't get the video to play for me.
 
Well, thanks for the diagnostic help everyone. Definitely the combustion fan that was buzzing.

It’s working for the moment.

I (1) removed the panel to check for any issues on the board, confirming everything was plugged in tight. I didn’t notice anything specific. (2) spun the combustion fan. It wasn’t bound, and spins freely. But then after a test, everything started up as normal.

So, perhaps just the motor is on its way out?

I recleaned the probe. And checked the fines box. It was 50% full it seemed, even though I had cleaned it out a month ago. Hard to find good pellets where I’m at :(
 
If it running now you may find after it is turned
off the next start up it will do the same thing
Order yourself a new fan and replace the old one
Better to have one on hand than not
 
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