P43 tech help

[Sawdust62]

i have a Harman P43 about 3 years old and trouble free until today. I came home and the stove was running, fully fired up, the switch was still in the "off" position. The temperature setting was at 60* but the house was easily at 75* when the stove auto ignited.
I could not get the stove to shut down regardless of what position the dials were in and unplugging and replugging it in did nothing. I had to empty the hopper so it would run out of fuel. I have no blinking lights.
Can anyone help me with a direction of which part went loco?
Thank you.

 

[Murph]

The stove was off for a while and then Just ignited? Perhaps board, would like a ddm reading of the esp probe to see what it is saying the temp is.

 

[smwilliamson]

Yep, that's why one doesn't leave the stove plugged in in the summer. You had a surge and it got creative with the source code. Bummer.

 

[Sawdust62]

The stove has been off for a few days. The "Room Temp - Stove Temp" knob was in the OFF position. After I emptied the hopper the stove shut down when it ran out of fuel. After it cooled I unplugged the stove waited a minute and plugged it back in, the fans came on as normal. Still no blinking lights.
I left it plugged in and again the knob was in the OFF position....about 2 hours later the stove tried to start up again but the hopper was still empty.

@SMW, I keep my stove unplugged in the summer. I live in upstate NY and we've had some crazy weather lately. I've been putting the stove on in the morning to take the chill off the house.
Thanks to anyone that can offer me guidance.

 

[MountainSean]

Pretty much the only thing I can think of which would cause the issue you are having is a failed control board. Possibly a bad ESP but I really doubt it would be the cause since the stove just starts up on its own.

 

[Sawdust62]

Thank you!
It makes sense....the stove shouldn't start up with the knob in the OFF position unless the board is bad.

 

[heat seeker]

If the ESP is bad, perhaps the stove suddenly thinks it's running and goes into shutdown mode???

 

[MountainSean]

If the stove started when it was plugged in even when in the off position I would suggest an ESP as a possible problem, but since the stove will sit for a couple of hours just fine and then start on its own it makes me think control board.

 

[Sawdust62]

The stove sat for 3 days with the knob in the OFF position and this problem started. Then it happened again a few hours later.

 

[Funnydirt14]

I vote the board, in particular the pot switch for the fan control. A bad ESP wouldn't start a stove when it's in the off position unless that switch was bad.

 

[Bioburner]

I had a bad pot switch on the PC45 and was firing up on its own. Replaced the pot and solved issue. Cheap and not to hard of a project if one has some experience with solder.

 

[Sawdust62]

Thank you guys for your help. Ive decided to replace the entire control board because when it did fire up on its own, none of the knobs seemed to respond to get it to shut down. After I emptied the fuel and it shut down as a result, I unplugged it and replugged it in.....Then the stove worked as it should. I turned it to OFF again and 2 hours later it did it again. My gut is telling me the problem is more than just one switch. I am board shopping now.

 

[smwilliamson]

$258 vs. $1.15

 

[Sawdust62]

Scott, are you saying I should just replace the fan control Pot Switch instead of the entire board? Don't you think that I have a bigger issue than just one Pot switch?
I respect your credentials and value your opinion. Thanks for your help.

 

[Bioburner]

The pot is common issue with Harman boards and is cheap to do versus board replacement. Don't over think or over pay as in this possible case. I have done two boards. The one place that does pot replacement will do a diagnostic too.

 

[mepellet]

Is the stove plugged into a surge protector?

 

[smwilliamson]

It's a pot issue provided you are assured the igniter is turning off after start up