Harman p38 ony runs on Turbo

[SirBarksalot]

When I went to start my p 38 this season. It would only power up When the feed rate hits turbo.
So I'm pretty much running it at Turbo. For a few hours to heat up the basement then turning it
off. I'm planning on replacing the circuit board. I was just wondering if anybody else has any Ideas
or had a similar problem

 

[MCPO]

When I went to start my p 38 this season. It would only power up When the feed rate hits turbo.
So I'm pretty much running it at Turbo. For a few hours to heat up the basement then turning it
off. I'm planning on replacing the circuit board. I was just wondering if anybody else has any Ideas
or had a similar problem

Being that control (feed rate and combustion blower ) is integral with the circuit board I see little choice but to replace it.

 

[rayers2]

Do you have a thermostat connected? I had this issue and a mouse had tried to make a dinner out of my thermostat wire and shorted it causing my P38 to go into turbo. When I checked the wire with a vom it was showing open but yet it was still running in turbo mode. Replaced wire and saw where it was nicked up from the mouse chewing on it. Strange that is was showing open and was still kicking the stove into turbo mode. If you do not have a thermostat connected then the board is next to replace...

 

[Cincinnati Kid]

What happens when you turn the feed rate down below turbo.....does the stop stop feeding pellets?

 

[Delta-T]

double check that the ESP probe is clean, if it cannot "feel the heat" at lower settings it might just be dirty.

 

[summit]

An interesting quirk i have seen with some harman stoves out in the field: when on lower feed settings, the fan speed decreases, thus lowering the availiable flow to the draft switch. the auger will not feed when its suppossed to, but if you cover over half of the air intake w/ your hand, viola! it creates added suction, and the switch allows the auger to turn... this is worth a try in your case... and instead of sitting there with your hand halfway covering the intake all season (like a little dutchboy w/ his finger in the dike) cover it up about 1/3 to 1/2 of the way w/ some foil tape.

 

[SirBarksalot]

Thanks for the info. I had a problem last year that turned out to be the Esp probe was shot. During that time I bought another circuit card. I put the old one back in today same problem. At that time I made some jumpers. Which I used to bypass each sensor until
I figured out which one was bad.
So thinking of that experience I'll check the probe and the draft switch. Be since it's Heating the room I'm in now I'll wait until tomorrow.
I don't use a thermostat. But when I bought the unit I had the intention of setting it up with one. After reading on how it goes Turbo to low and back. I thought it would be more efficient to leave it on one setting. Is it noticeable? Are you happy with it?

 

[Dl Mahan]

Hello, I need help/advice on my P38. Last year I replaced both the circuit board and ESP at the same time. Stove ran great, until today. Been running it for about 1 month all day/night. Today it quit and couldn't get it to start and continue to run until I turned it on Turbo. I noticed one of the motors or fans was running on and off. We cleaned the ESP and when we pulled it out the motor or fan started to run again. We put the ESP back in and it quit, we did this a few times to make sure it was not a quirk. It's running on Turbo but can't do this all the time. Is it the ESP? I called the dealer, although it is out of warranty and was told it would be three weeks before they could look at it. This is the sole heat in my 86 year old mothers unit, so I obviously cannot wait three weeks - I live in Maine. Any advice would be greatly appreciated. Thank you. If I posted in the wrong spot - sorry - never posted anything before - I'm desperate!

 

[Dl Mahan]

Hello, I need help/advice on my P38. Last year I replaced both the circuit board and ESP at the same time. Stove ran great, until today. Been running it for about 1 month all day/night. Today it quit and couldn't get it to start and continue to run until I turned it on Turbo. I noticed one of the motors or fans was running on and off. We cleaned the ESP and when we pulled it out the motor or fan started to run again. We put the ESP back in and it quit, we did this a few times to make sure it was not a quirk. It's running on Turbo but can't do this all the time. Is it the ESP? I called the dealer, although it is out of warranty and was told it would be three weeks before they could look at it. This is the sole heat in my 86 year old mothers unit, so I obviously cannot wait three weeks - I live in Maine. Any advice would be greatly appreciated. Thank you. If I posted in the wrong spot - sorry - never posted anything before - I'm desperate!

It also will not start up on anything but turbo, if I turn it down while it's starting up it quits, so I turn it back up to turbo and start up continues.

 

[MCPO]

It sounds to me like the feed control potentiometer is bad. I had to replace mine last year. This is a common issue with the P-38 control board.I bought mine on Ebay for approx $10. Any electronic tech or TV repair guy can change it out for you.

 

[Dl Mahan]

It sounds to me like the feed control potentiometer is bad. I had to replace mine last year. This is a common issue with the P-38 control board.I bought mine on Ebay for approx $10. Any electronic tech or TV repair guy can change it out for you.

Thank you so much for your reply. Can these be purchased anywhere else locally. I need to get this up and running ASAP for my mother. I have been running on Turbo but have to keep shutting it down as it gets too hot. How do you ID this part? My neighbor is good at these type of repairs - he is an aircraft mechanic and quite capable and willing, but isn't familiar with pellet stoves. So as I understand it this is part of the circuit board? Thanks again, you don't know how much I appreciate answers I have trouble shot this thing all day yesterday and again this AM.

 

[ducker]

It sounds to me like the feed control potentiometer is bad. I had to replace mine last year. This is a common issue with the P-38 control board.I bought mine on Ebay for approx $10. Any electronic tech or TV repair guy can change it out for you.

Unless you personally know a electronic tech/tv repair guy, I'm not sure if one is going to want to make a house call to work on a pellet stove. So what exactly is needed to be done here? Just some wires disconnected and re-soldered on to the board?

 

[MCPO]

Thank you so much for your reply. Can these be purchased anywhere else locally. I need to get this up and running ASAP for my mother. I have been running on Turbo but have to keep shutting it down as it gets too hot. How do you ID this part? My neighbor is good at these type of repairs - he is an aircraft mechanic and quite capable and willing, but isn't familiar with pellet stoves. So as I understand it this is part of the circuit board? Thanks again, you don't know how much I appreciate answers I have trouble shot this thing all day yesterday and again this AM.

It`s soldered onto the board .You would need to pull all the wires off the control board (take pictures or draw one ) so you know where wires go back, and then remove the board .Then you have to remove the old pot (soldered and tabs bent onto board).You definitely need a solder extractor (solder sucker) because without one you can`t get at the bent over tabs that hold the pot onto the board.
Maybe at radio shack you get something similar, I don`t know.

 

[MCPO]

Unless you personally know a electronic tech/tv repair guy, I'm not sure if one is going to want to make a house call to work on a pellet stove. So what exactly is needed to be done here? Just some wires disconnected and re-soldered on to the board?

I was thinking the stove owner could remove the board and bring it to someone who knows how to do the solder job.
It`s not a 2 minute simple solder job. It`s a delicate board and the pot isn`t quite as easy as it looks to remove cleanly. Whoever does it has to have some degree of experience .