Harman P43 won't shut down

[NJnetguy]

Good morning,
new guy here, but not new to the stove. I've had this P-43 for going on 7 years now, and up till this season haven't had an issue with it at all.

Currently, its set to room temperature, (70 degrees) normal feed rate, and the blower fan is on a fairly high setting. It will burn through a normal cycle, cool down, and when I'm fairly certain it's about to shut down completely, it starts dumping pellets into the burn pot again, restarting the whole cycle.

If I turn the temperature down to 68, operates normally, and will shut down.

I'm inclined to think it's either the thermostat, or a dirty or bad pot on the control panel.

Can anyone offer any insight?? Thanks in advance.

 

[scajjr2]

I'd check the connections of the room temp probe (reseat them just to be sure) then try some electronic contact cleaner in the pots on the control board. Possible the room temp probe is going.

sam

 

[Mt Bob]

I'm inclined to believe the stove is just dealing with the heat loss of the house/room.

 

[NJnetguy]

I'm inclined to believe the stove is just dealing with the heat loss of the house/room.

In the years I've had the stove, I've found that it's around a 4-5 degree temperature drop in the room where the stove is before it will kick back on, in this case it's not dropped a full degree from the temp the stove is set to.

 

[NJnetguy]

I'd check the connections of the room temp probe (reseat them just to be sure) then try some electronic contact cleaner in the pots on the control board. Possible the room temp probe is going.

sam

I've got the bottle of Deoxit ready to go but hadn't used it yet as the stove hasn't kicked on in a few days. We were pushing 70 outside temps here this week- at least until this morning. I will unplug and reseat the connections on the probe and see if that helps. Thanks!

 

[johneh]

I'm inclined to believe the stove is just dealing with the heat loss of the house/room.

X2

 

[Northwoodneil]

Make sure you didn't bump the ignition switch to manual instead of auto.

 

[Northwoodneil]

Sorry didn't read the part about it shutting down at 68*

 

[Mt Bob]

1-a new room sensor is cheap
2-a dirty stove can really screw things up with the exhaust probe, which can affect this situation
Also, things like new windows. moving furniture around,etc can affect the airflow in a room, over the sensor.

 

[NJnetguy]

1-a new room sensor is cheap
2-a dirty stove can really screw things up with the exhaust probe, which can affect this situation
Also, things like new windows. moving furniture around,etc can affect the airflow in a room, over the sensor.

I'm a weekly cleaner-and did the exhaust probe last week.
We haven't moved a thing in the room in quite some time.
I'm ordering the new wire today!

The thing that throws me for a loop is the normal operation at 68 or 72 - what keeps bringing me back to the bad/dirty pot is the fact that this only occurs at the 70-degree setting.

 

[Mt Bob]

Have you cleaned the pots lately? If not, try it.

 

[bogieb]

Since it runs normally at 68*, I'm inclined to go with the pot theory. Most likely have a "dead" spot.

 

[NJnetguy]

Have you cleaned the pots lately? If not, try it.

I cleaned them last night after reading all the comments, no change.
Inclined to run it at 72 until I can get some new pots.

does anyone know of a source for them other than ebay?
i'm fully capable of changing them out, just figured I'd be able to find them for less than $10 per

 

[jordan69s]

I know of a P68 pellet stove that is doing the same thing. Is the advice above the same for this pellet stove?

Also: "bad/dirty pot," Are you referring to the burning pot that the pellets combust?
Where is the exhaust sensor? And can this cause this no-off problem? How does it get clean?

Thank you in advance for your answers.

lme

 

[bogieb]

I know of a P68 pellet stove that is doing the same thing. Is the advice above the same for this pellet stove?

Also: "bad/dirty pot," Are you referring to the burning pot that the pellets combust?
Where is the exhaust sensor? And can this cause this no-off problem? How does it get clean?

Thank you in advance for your answers.

lme

Dirty pot = dirty potentiometer. In this case, the temp dial (or probably more accurately, where the dial meets the board - IDK, I'm not an electrical type of person).

If the P68 is not starting and/or stopping as expected at a set point (say 72*), but works correctly on another set point (say 68*), the odds are the issue is the same.