Harman P38 issue

[Bob_LobLaw]

Please help. I have a harman P38 pellet stove that will only work when the heat is turned up all the way. Everything works fine at full throttle but nothing otherwise. It has the old style, two knob setup on it.

Thanks!

 

[Overfireinthehole]

I can’t remember if room temp is an option on those older ones. If so and that’s what your using, could be a bad sensor. If not, could be a dirty or bad esp. baring all that, the potentiometer on your board dial could be going out. If your good with a solder gun, you can get those pots cheap and replace. Otherwise, your looking at a new board.

 

[Bob_LobLaw]

I can’t remember if room temp is an option on those older ones. If so and that’s what your using, could be a bad sensor. If not, could be a dirty or bad esp. baring all that, the potentiometer on your board dial could be going out. If your good with a solder gun, you can get those pots cheap and replace. Otherwise, your looking at a new board.

Thanks for the response. A bit more info...

It doesn't have the temperature control, just the blower and feed rate knobs.

I just tried to run it at full throttle and the fan stops after about a minute or two and then it just feeds the pellets even though the stove itself is hot enough to engage the convection blower.

 

[gfreek]

1] ESP sensor, clean or replace 2] bad potentiometer [ control knobs], replace, 3] bad control board..Also I would test convection blower make to sure it's not stopping after being on awhile..

 

[Bob_LobLaw]

1] ESP sensor, clean or replace 2] bad potentiometer [ control knobs], replace, 3] bad control board..Also I would test convection blower make to sure it's not stopping after being on awhile..

Thanks for the suggestions. I'll see if I can clean it up!

 

[gfreek]

Also you could try cleaning the "pots" for feed & blower control knobs, maybe with some CAIG DeoxIT, or similar electronics cleaner, to clean them. Unit unplugged of course..

 

[Bob_LobLaw]

Also you could try cleaning the "pots" for feed & blower control knobs, maybe with some CAIG DeoxIT, or similar electronics cleaner, to clean them. Unit unplugged of course..

Awesome. Thanks!

My brother in law is an electric engineering tech and he's going to take a look at it for me. I'm not very handy. The worst part is that I've already sold the house so I need to get the stove in working order ASAP. And given the costs of moving, I'd love to not have to replace the whole board.

Thanks for all the help!

 

[gfreek]

I'd love to not have to replace the whole board.

The replacement board is upgraded to a three knob board..
(broken link removed to http://pellethead.com/product/harman-harmon-control-circuit-board-p61-p38-invincible-insert-invincible-rs-super-mag-stoker-part-3-20-00928-3-20-05378-3-20-05890-3-20-06142-1-00-06142/)

 

[Overfireinthehole]

The replacement board is upgraded to a three knob board..
(broken link removed to http://pellethead.com/product/harman-harmon-control-circuit-board-p61-p38-invincible-insert-invincible-rs-super-mag-stoker-part-3-20-00928-3-20-05378-3-20-05890-3-20-06142-1-00-06142/)

I wonder if you have to replace the harness to do that?

 

[gfreek]

I wonder if you have to replace the harness to do that?

It comes with a harness . Plug on one end to plug into board, pig tails on the other to connect to your harness (auger, combustion, convection motors). ESP plugs into board.. Instructions included. Again check other components first..This shows harness and cut out template..
(broken link removed to https://www.ebay.com/itm/P38-Circuit-Board-/222806399479?_trksid=p2349526.m4383.l4275.c10)

 

[bags]

Agreed. Start with the ESP. Then clean the knobs for a quick and dirty possibility. Roll them back and forth while using an electrical spray cleaner. Bottom line...... The old two knobber has some miles and time on that setup. Good Luck!

 

[Bob_LobLaw]

So an update. It was the ESP so I just received the replacement part.

One more question. When my brother in law was working on the stove, we took it off where it connects to the chimney. In the process we ruined the ceramic wool gasket. Any ideas as to the thickness of the ceramic wool that I should buy? The piece that was there was pretty degraded so it tough to tell.

Thanks!

 

[Bob_LobLaw]

So an update. It was the ESP so I just received the replacement part.

One more question. When my brother in law was working on the stove, we took it off where it connects to the chimney. In the process we ruined the ceramic wool gasket. Any ideas as to the thickness of the ceramic wool that I should buy? The piece that was there was pretty degraded so it tough to tell.

Thanks!

This is where the gasket was. I'm not even certain what the material was, I'm just assuming it was ceramic wool.

Thanks

 

[jzm2cc]

Standard Harman tail pipe gasket. Probably made from fiberglass.

Part number
3-44-06179.

 

[Bob_LobLaw]

Th

Standard Harman tail pipe gasket. Probably made from fiberglass.

Part number
3-44-06179.

Thanks so much. This is the most knowledgeable community I've ever interacted with on the internet. You guys are the best

 

[gfreek]

Great you're up and running. Thanks for the update.