Harman P68

[SininStyle]

So fired up the pellet stove and let it run all day for the first time this season because it was a bit chilly. It ran fine and shut off fine. No issues at all.
Few days later I ran it over night, no issues.
Last night I run it all night and get up this morning to find the combustion blower is on, the fire is out, and there is plenty of pellets left. So I figure it ran out of pellets, it shut down, then they fell from the sides. So I set it to "Off" and give it a min. The combustion blower doesn't shut off. Odd ok so I leave it and still doesn't shut off. So I put it to stove temp/high and let it feed pellets and do its thing. The pellets keep coming until they overflow and it doesn't ignite.
At this point I am concerned. This is not how I wanted to start the season at all. So I give it a good cleaning hoping the igniter is blocked or something. Leave it unplugged for an hour hoping to clear the board. Plug it back in with the same result.

So looking online it is a coin toss between a ESP and the circuit board. At $100-$300 each I am really hoping someone here had better news. Some hope that I missed something.
Any help would be greatly appreciated.

 

[Delta-T]

was the status light blinking at all?

 

[Delta-T]

i would lean more towards the ESP. You have unit on surge suppressor?

 

[SininStyle]

I do not.

 

[SininStyle]

I do not remember seeing any blinking. I have it on now after all the previous was done and no blinking.

 

[SininStyle]

looking for blinky lights I just realized its not just combustion it is also the distribution blower. But the distribution blower is for the most part idle speed. speed it is at when its cold.

I replaced the distribution fan at the start of the season as last yr it was squeaking but like I said it worked for 3 days fine so I don't think its the wiring.

 

[SininStyle]

Pulled the ESP and shined it up nice , same result after reinstalling

 

[Delta-T]

honestly, without a diagnostic tool attached, I can only guess that its the ESP probe giving a bad reading to the board, and the board assuming the stove is at an operating temp, and doing what it thinks is appropriate. DOes the igniter light come on if you put the stove into room or stove temp?

 

[SininStyle]

Yup, all lights come on when I turn it on.

 

[Delta-T]

does the igniter get hot?

 

[SininStyle]

I don't know much about these things. Is there anyway to trouble shoot it? Can i unplug the ESP and run on room temp an expect it to shut off? Or is ESP needed for both settings?

 

[SininStyle]

does the igniter get hot?

it has been on for a while and no it doesn't feel warm on the pot at all.

 

[Delta-T]

the ESP is required for pretty much everything. Its the only thing in the machine that measures the temperature. it tells the fans when to turn on/off, when to tell the auger to feed...everything. If you unplug the ESP, you should get a 3 blink status light error, you could do this, just to make sure the board is at least communicating with the probe.

 

[Lousyweather]

be curious what the ESP reading on a DDM would be.....I think the "magic" number for a bad, room temperature ESP is around 452 degrees or so......when it should be 70

 

[Delta-T]

curious indeed. I've sen the 400+ many times...saw a 700+ last year. those micro-farads can be sneaky.

 

[Lousyweather]

basically, watch the status light and see how many blinks you are getting when this is happening....maybe try a manual reset as well (unplug, count to 5, plug back in)

 

[SininStyle]

ive done many manual resets, no blinking, problem continues.
I was going to disconnect the probe but it has some weird crimp on it. nothing I recognize. has some dark yellow clear plastic in the center. not even sure how to unfasten it.
stil no blinking lights for either settings. but everything seems to fire up when i set it to stove/room , hear the auger go ect.

 

[Delta-T]

you'd have to disconnect it at the control board. unplug it first.

 

[SininStyle]

ok got the panel off, unplugged the probe, plugged in the stove, it spun the fans up just like it has been but now status blinks 3 times.

 

[Delta-T]

well, the lesser expensive thing to do is replace the ESP probe. Unfortunately there isn't anything else you can do to diagnose the problem. It is either teh ESP, the Board, or both....sadly, even my powers have limits . These type-o things are often the result of funky power issue...power spike, power glitch, lightning strike kinda things....do get a surge suppressor to insulate you from future attacks of the stove gnomes. If you have friend/dealer local with Harman Diagostic tool..is an easy problem to root out.

 

[SininStyle]

I am actually in NH, know of any dealers close to Concord that might have the part in stock? Only one I see is Wakefield, an hour away.

 

[Delta-T]

should be in stock for any dealer IMO. you can use dealer locator on Harman web site to find closest dealers, i'm not really sure who is close to you.

 

[SininStyle]

thanks, was looking at local dealers but none showed they carried parts, at all. just shows stoves. that opens up some options

 

[holstein]

It might not meet your definition of local, but Stove Keepers in Brookline, NH stocks plenty of Harman parts and they are open 7 days a week.

 

[Lousyweather]

most dealers will stock parts, especially the ESP......cant imagine a dealer who services stoves NOT having that part, in fact......

3 blink now? as might have been said above, 3 blink is almost always the ESP.....make sure you get the right one, and when you do get the probe, ensure that the switch #5 on the circuitboard corresponds to that probe (ON=red wire probe, OFF=black wire probe)......they are different, and the wrong setting will result in your stove faulting out.......

as an aside, sounds to me like someone has replaced your ESP in the past. That crimp connector with the yellow push thingy in it was only available on replacement ESP probes (black wire only) for awhile.....it allowed the user to not have to cut wire ties, but what was found out was that it didn't always work....sometimes the splice wasn't good, sometimes the user didn't crimp it enough, etc......its no longer available and hasn't been for a year or two. That being said, Im hoping your switch 5 is set to OFF, since in all likelihood you have a black wire (analog) probe

if you check the resistance on the red wire probe while it warms up, you'll see the resistance rise, whereas, with the black wire probe, it falls