I have a Harman P68 Pellet stove that will not ignite and is not acting right. It acts like their is heat all of the time; when you plug it in even in the off position the combustion blower will come on even when the unit is cold. I replace the ESP sensor in the exhaust thinking that was the problem but it is still doing it. The ignitor light never comes on even though it is set to off. We also replaced the room temp sensor as well as the combustion blower which was bad. The ignitor tests fine... I am reading around 50ohms on the multimeter and when I apply power directly it does heat up. Should I be looking at a new control board? I am not sure how to test the auto/manual switch (not sure what is suppose to be open/closed in different positions). Any help would be greatly appreciated.
Harman P68 Not Igniting
- Thread starter David Bell
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Harman Lover 007
Minister of Fire
In test mode the auger turns... but the ignitor still does not get any power.
Bioburner
Moderator
How old is the stove? Improper vac will stop stove from igniting. Combustion motor will come on from a power out as a safety. Also stays on for up to an hour after fire out.
No blinking lights... I had a esp blinking light but after I changed the room sensor it stopped blinking...
I will try bypassing the vac switch to see if that resolves the problem... also... the switch is set to auto, not manual... and the stove was made in 2005.
Bioburner
Moderator
I would lay good odds that the door gaskets need replacing. Three to five years is probably average for them. Not a hard or very expensive project. Can improve fire by improving air flow where its supposed to go.
Harman Lover 007
Minister of Fire
Ok Dave, it sounds like you are fairly well versed in your stove. What color are the wires on the new ESP compared to the old one, red or black? You say the combustion blower runs all the time? It sounds like you have done a hard reset by unplugging and plugging the stove back in..yes? Are you sure the exhaust path is clear? Hang in there, we should be able to figure this out.
I switched the #5 dip switch and still the same issue. I did do a hard reset. Exhaust is free and clear... is the ignitor suppose to come on right off or is there a delay?
As mentioned above, after a ignition cycle, are you getting any blinks on the status light? if so, how many?
Dip switch....#5 should be OFF if its a black wire to the ESP, ON if its a red wire...
since you've tested the resistance of the igniter, I assume you've taken it out......did you replace to cradle cover correctly?
are the holes in the burnpot clear?
I don't think its the gasketing, as youre feeder is turning.....if it were a bad gasket, most likely, you'd get no feed
lol- make sure your thermostat on the stove is turned way up.....
don't screw around with the dip switches too much, as they also control the amount of time the igniter is powered.....might mess stuff up
Does the burnpot get warm at all after an ignition cycle?
See any smoke or "sparks" (fines igniting) on the ignition cycle?
Don't think its a pathway obstruction, as the stove is feeding (magnehelic would be beneficial here)
Upon ignition, does the circuitboard light come on? (this is pretty important- light doesn't come on in test mode, and would tell us if the CB is trying to power the igniter or not)
Circuitboard? maybe, but you've got more work to do before that...
Dip switch....#5 should be OFF if its a black wire to the ESP, ON if its a red wire...
since you've tested the resistance of the igniter, I assume you've taken it out......did you replace to cradle cover correctly?
are the holes in the burnpot clear?
I don't think its the gasketing, as youre feeder is turning.....if it were a bad gasket, most likely, you'd get no feed
lol- make sure your thermostat on the stove is turned way up.....
don't screw around with the dip switches too much, as they also control the amount of time the igniter is powered.....might mess stuff up
Does the burnpot get warm at all after an ignition cycle?
See any smoke or "sparks" (fines igniting) on the ignition cycle?
Don't think its a pathway obstruction, as the stove is feeding (magnehelic would be beneficial here)
Upon ignition, does the circuitboard light come on? (this is pretty important- light doesn't come on in test mode, and would tell us if the CB is trying to power the igniter or not)
Circuitboard? maybe, but you've got more work to do before that...
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The ignitor is getting no power at all... tested the leads off of the control board and am getting nothing. The ignitor light never comes on at all. The status light blinks a couple of times when you first plug it in and then remains steady on. The only dip switch I have changed is the #5 dip switch which doesn't seem to make any difference at all.
Is the combustion blower suppose to come on when you first plug it in even if the unit is turned to the off position? The blower comes on and stays on when you first plug it in... it is acting like it is hot all of the time.
Burnpot never gets warm... no sparks.... nothing. If the ignitor was bad would the ignitor light still come on? But that still would not explain why there is no power to the ignitor.
the combustion fan might come on and stop pretty fast upon plugging in, but set on OFF, shouldn't stay on if there is no fire....those OFF positions are pretty touchy though.....
kneejerk is ESP (which you said you changed?), or the circuitboard........
if the ignitor was bad, light would still come on.......
the key here being the stove is feeding......you purists out there might note that the igniter does route thru the vac switch, but on that same terminal, so does the feeder, so, if the feeder is feeding, its not the vac switch....
kneejerk is ESP (which you said you changed?), or the circuitboard........
if the ignitor was bad, light would still come on.......
the key here being the stove is feeding......you purists out there might note that the igniter does route thru the vac switch, but on that same terminal, so does the feeder, so, if the feeder is feeding, its not the vac switch....
The combustion blower comes on and stays on all of the time no matter if it is set to off or not. With it on the 'off' position, the auger will not feed so it seems that the off switch is working OK. It seems as though the ESP Sensor is telling it the unit is hot all of the time. I did replace the ESP Sensor so my gut feeling is telling me the circuit board is bad.
Bioburner
Moderator
The pot switches are known to go bad as they have a limited cycle life. I got three off ebay couple weeks ago for $9 delivered. Not a hard project if you have experience with soldering.
P38X2
Minister of Fire
If you do end up needing to replace the circuit board, do yourself a favor and DON'T take the contortionist route unless the 68's board is easily accessible for you. Tip the stove on its side or do whatever you have to do to be able to get at the board as easily as possible. I'm assuming all P series stoves use the same board fastening method which is 4 pins that the board is pushed onto.
The tips of the pins have a split in them and several things can go wrong if you have to blindly try to align the holes in the board. You may accidentally close the gap in the pins causing a loose fit or catch the edge of the hole in the board on the pin causing it to splay apart. If you force the board on in this case, you may end up inadvertently opening the diameter of the holes on the board causing you to need to stick a utility knife blade, or something similar, in the pin split to pry it open a bit. Open it too much and you may end up "chasing" the proper gap. This whole time you're likely to be cutting the crap out of your arm on various sharp edges.
Maybe the 68 has more room to work or maybe you'll get lucky and line it up on the first attempt. If I had to re-mount my board again, which I probably will due to the fact mine fits loosely, the stove will be getting tipped on its side or front. I've done many repairs on things in tight spots or difficult angles, and that fricken board is probably at the top of that list.
You seem highly competent with what you're doing but I gotta remind you to unplug the stove when working on it, especially the board. When freeing a jammed slide plate, I accidentally shorted something on my board. Fortunately, the fuse popped. Unfortunately, this required the board to be dismounted to replace it. IMO, the method Harman uses to secure the board on the 38's and probably your stove is stupid. Why it isn't secured with 4 screws from the OUTSIDE of the stove is straight up stupid.
Of course, this whole rant might be pointless as you probably have already removed it to do your testing.
Best of luck getting her back up and running.
The tips of the pins have a split in them and several things can go wrong if you have to blindly try to align the holes in the board. You may accidentally close the gap in the pins causing a loose fit or catch the edge of the hole in the board on the pin causing it to splay apart. If you force the board on in this case, you may end up inadvertently opening the diameter of the holes on the board causing you to need to stick a utility knife blade, or something similar, in the pin split to pry it open a bit. Open it too much and you may end up "chasing" the proper gap. This whole time you're likely to be cutting the crap out of your arm on various sharp edges.
Maybe the 68 has more room to work or maybe you'll get lucky and line it up on the first attempt. If I had to re-mount my board again, which I probably will due to the fact mine fits loosely, the stove will be getting tipped on its side or front. I've done many repairs on things in tight spots or difficult angles, and that fricken board is probably at the top of that list.
You seem highly competent with what you're doing but I gotta remind you to unplug the stove when working on it, especially the board. When freeing a jammed slide plate, I accidentally shorted something on my board. Fortunately, the fuse popped. Unfortunately, this required the board to be dismounted to replace it. IMO, the method Harman uses to secure the board on the 38's and probably your stove is stupid. Why it isn't secured with 4 screws from the OUTSIDE of the stove is straight up stupid.
Of course, this whole rant might be pointless as you probably have already removed it to do your testing.
Best of luck getting her back up and running.
the P68 control board facing is held in place by two screws.....just unplug the stove, open the control panel door, remove the two screws (on the upper and lower right of the control panel facing the panel), and the panel will come out the front.....pry the board off the standoffs, unplug everything, plug the new one in, re-secure......pretty easy.....should take all of 5 minutes......be advised though, that you pay attention to the directions which are with the board......don't simply use the same dipswitch settings as your old board, assuming they are the same......again, switch 5 to ON if the ESP wire is red, switch 5 to OFF for black......
I wonder if maybe the replacement ESP is bad? We use a DDM to determine what that little devil is reading, because we can do it without replacing anything....ya just plug one in.....it tells you what the ESP is reading, temperature-wise. So, on a cold stove, if that ESP is reading 520 degrees, well, the ESP is bad........should read ambient temp in an OFF (and cool!) stove.
I wonder if maybe the replacement ESP is bad? We use a DDM to determine what that little devil is reading, because we can do it without replacing anything....ya just plug one in.....it tells you what the ESP is reading, temperature-wise. So, on a cold stove, if that ESP is reading 520 degrees, well, the ESP is bad........should read ambient temp in an OFF (and cool!) stove.
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Harman Lover 007
Minister of Fire
I was just typing this and you beat me to it. The P61A and P68 boards are a 5 minute swap, tops.
P38X2
Minister of Fire
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