Harman P35i - multiple isssues

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Joon16

New Member
Feb 2, 2021
7
Pittsburgh
Hello everyone,

I searched everywhere trying to find out what is wrong with my pellet stove but the symptoms have changed a few times and I am not knowledgeable enough to know what they mean. It started out 3 days ago. We woke up and the stove was completely off. I took it apart and noticed that the fuse was blown. Replaced the 6a 250v fuse and it blew immediately after turning on. After reading some, we found the ignitor to be a common reason for this so we purchases an OEM ignitor. Installed the ignitor, put a new fuse in, and it started up no problem. Ran for about 5 minutes and the fuse blew again. So we tried to manually light the stove with the yellow ignitor wire disconnected to see if that was the cause of the fuse blowing. The stove runs now without the ignitor connected but the distribution blower runs for 30 seconds, then shuts off for 2 minutes. The timing of this is consistent and almost exact. Also, the "room temp" feature can be set to control how hard the distribution fan blows but no matter if it is low or high, it blows the same. So it appears this isn't working other than the fact that it must on in order to have the stove running at all. If we had it in the off position, the stove would not light since there is no combustion blower running. At this point I am thinking it may be the control panel but before spending over $200 I was hoping someone here could tell me what I can test or check to make sure. Another thought was the ESP probe but I am not really sure. Thanks in advance for the help.
 

Washed-Up

Minister of Fire
Nov 5, 2011
780
Kananaskis,Alberta, Canada
I would check all of the wires to each component and follow them back to the board to ensure no wires have bare spots and touching each other, as well as the connections at the motherboard. It sounds like you have a short somewhere....start with the igniter wiring back to the board.
 

Joon16

New Member
Feb 2, 2021
7
Pittsburgh
I took a look and didn't see anything but I will double check. We initially thought that was the problem with the ignitor from cleaning out the tray but since it has been replaced that must not be it. If it is a wire elsewhere, can I use electrical tape or does the wire need replaced entirely?
 
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Washed-Up

Minister of Fire
Nov 5, 2011
780
Kananaskis,Alberta, Canada
Electrical tape will work, just need to cover it so it stops the short....then have a better look at it during summer
 

rickwai

Minister of Fire
Nov 1, 2011
1,204
ohio
It is very common for the Comb blower motor to cause the instant fuse blow as soon as the stove is plugged in. If you have ever noticed the comb motor momentarily comes on as soon as the stove is plugged in even if it is in the off position.
 
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Joon16

New Member
Feb 2, 2021
7
Pittsburgh
We will be changing out some parts, checking all the wires, and swapping our control board onto a different unit to see if we can determine the problem. Thanks for all the suggestions. I will post once we have more info so this thread can be used in the future if someone experiences the same series of events.
 
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Joon16

New Member
Feb 2, 2021
7
Pittsburgh
It is very common for the Comb blower motor to cause the instant fuse blow as soon as the stove is plugged in. If you have ever noticed the comb motor momentarily comes on as soon as the stove is plugged in even if it is in the off position.

*EDIT* I pulled the stove out and plugged it in to see if the combustion blower came on. It did for a few seconds and then turned off. The distribution blower continues to run once plugged in and in the off position but the combustion blower turns off after a second or two.

Electrical tape will work, just need to cover it so it stops the short....then have a better look at it during summer

I also checked all wires, nothing seems to be frayed or exposed. Will be replacing the ESP sensor today and possibly the control panel. We put the control panel on a separate stove to see if it would work and it started the stove fine, no fuses blew, but it continued to feed pellets after the stove was turned off.

Right now we manually lit the stove for some heat with the ignitor disconnected (fuse blows if ignitor is connected). It runs but the distribution fan is still turning on and off even with the light for it lit up.
 
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Joon16

New Member
Feb 2, 2021
7
Pittsburgh
Check the new igniter for shorts.
I pulled it out, looked it over, and reinstalled. Didn't notice any exposed wire. Tried to start the stove up with everything attached. It lit for and lasted about 2-3 minutes before the fuse blew. Distribution fan still runs constantly. Any other way to look for shorts?
 

rickwai

Minister of Fire
Nov 1, 2011
1,204
ohio
On the igniter, did you get a OEM Harman igniter? I cant ever remember having a bad one out of the box in the last 10 yrs. I run 2- 6 service calls a week on Harmans and I have only replaced I think 1 bad igniter. The other one was preventive maintenance on the fall cleaning, it had a old 11 ring igniter that was looking pretty rough and they live about a hour from the shop.
 

Joon16

New Member
Feb 2, 2021
7
Pittsburgh
On the igniter, did you get a OEM Harman igniter? I cant ever remember having a bad one out of the box in the last 10 yrs. I run 2- 6 service calls a week on Harmans and I have only replaced I think 1 bad igniter. The other one was preventive maintenance on the fall cleaning, it had a old 11 ring igniter that was looking pretty rough and they live about a hour from the shop.
We did buy an OEM ignitor from our local dealer. Since the fuse has blown with the ignitor wires disconnected (yellow wires at the control panel), I think I can rule out the ignitor as a problem.
 

rickwai

Minister of Fire
Nov 1, 2011
1,204
ohio
Comb blower motor is most likely then
 

Joon16

New Member
Feb 2, 2021
7
Pittsburgh
Comb blower motor is most likely then

Any way to test if this is it or just buy and replace the motor? The comb motor is technically working since we are still able to keep the stove lit. Not saying there isn't a problem with it, just laying out all the info I can.
 

rickwai

Minister of Fire
Nov 1, 2011
1,204
ohio
Im sure there is if you bring it to a motor shop. I dont know the inner workings of them. I just know from 14 yrs experience servicing Harmans that the 2 things that typically blow the board fuse are the igniter and the Comb. motor. I have had a bad board once that was taking the fuse out but never a Dist blower or auger motor that I can remember.
 

Ssyko

Minister of Fire
Nov 6, 2017
4,256
Lorraine NY
open frame motor's tend to suck in dust and lint and it collects in the windings and armatures and they don't cool like they should. Heat is the biggest enemy of an electric motor and when they long periods without cleaning and living in a warmer climate than normal the winding are coated with a shelac that when overheated will deteriorate and the wires can short and it will overheat and shut down. or in early stages just create more resistance in the windings, thus creating more heat. it could be the warning of an immanent failure
 
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