Harman P68 Never Shutting Down

[derek456]

Hello,

I have a Harman P68 pellet stove that is the main source of heat in my house. In December, the stove began to constantly burn pellets until the hopper empties, regardless of the room temperature. We woke up one morning to a 90 degree house! Here is what I know/have tried:
- The stove is being run in room temperature mode.
- After running out of pellets, the stove does not start until the temperature dips below the setting on the control panel.
- After the fire starts, the room temp/stove temp knob can be turned to OFF, and the stove will continue to burn indefinitely (overnight, if I put enough pellets into it).
- I have replaced the control board and the ESP probe that checks the temperature of the output air.
- The "status" error light is not blinking at any point.

I am tempted to replace the room temperature sensor, but since the stove starts correctly, it would seem that this part is working properly.

Any ideas on what the problem could be? I would appreciate any suggestions you may have!

 

[DAKSY]

How does it run on STOVE temp?

 

[derek456]

How does it run on STOVE temp?

I haven't tried it on STOVE temp mode. The user manual said that makes it run indefinitely for a nice viewing flame while not blowing excess heat into the house. That didn't seem like a step in the right direction to me.

 

[DAKSY]

Well, until you figure it out, you can run it that way, set to low & be able to manage your fuel consumption.
Meantime take your room sensor to a hearth shop & see if it works on a floor model...

 

[Harmanizer]

I haven't tried it on STOVE temp mode. The user manual said that makes it run indefinitely for a nice viewing flame while not blowing excess heat into the house. That didn't seem like a step in the right direction to me.

You are incorrect on stove temp.Reread the manual.I use my unit in stove temp almost all the time.How old is the stove?Did you replace with a black wire esp or red wire?Dip settings may be wrong.

 

[derek456]

You are incorrect on stove temp.Reread the manual.I use my unit in stove temp almost all the time.How old is the stove?Did you replace with a black wire esp or red wire?Dip settings may be wrong.

Looks like you're right, I misunderstood it - I will try it in stove temp mode.

I replaced it with a red esp, same as it had before. Dip settings are matched to the control board I replaced.

 

[The Grintch]

Sounds like an ESP issue.

 

[derek456]

Sounds like an ESP issue.

As per the post, it has been replaced already.

 

[Nitro-Fish]

Just because it was replaced doesn't mean it's good; you may have purchased a bad probe. I would run it in stove temp to see how it acts, if it still acts up I would say ESP. The ESP being bad will let the stove act like you are describing. Double check the board settings as well, set to the instructions that came with the board.

 

[The Grintch]

So what was the issue/fix?