Harman P68 Ignition Problems

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Rokey199

New Member
Dec 19, 2023
8
PNW
My stove had Intermittent ignition problems towards the end of last season (runs fine once it is manually lit) so I ordered a couple of new ignitors both test @ 50 ohms and when connected to 120V glow red hot. I did a thorough cleaning, pulled the combustion and distribution blowers and cleaned, pulled and cleaned ESP, inspected and cleaned the air intake, vacuumed out fines box, cleaned out all of the small holes in the burn pot above the ignitor, installed the new ignitor and replaced the door gaskets ... same results. (same with the second new ignitor, also checked to make sure the ignitor was properly installed tight to the burn pot)
Also tried different pellets with the same results
The ignitor light on the circuit board comes on for the 30 minute cycle or however long it is and the pellets feed fine.
With the long wait times for service this time of year and the age of the stove (2007) I figured I would throw some new parts into it to try to solve the problem or at least have some spares. First I installed a new circuit board, it fired off a couple of times then started throwing the 5 blinks code every time it tried to light, I continued to use it with manual lighting. After about a week I noticed excessive black soot and a lazy fire so I replaced the combustion blower, That problem was now fixed.
I had a service tech out last week (a previous but not current Harman dealer) checked everything out and suspected a bad circuit board (I returned the new board and picked up another one), He said everything else looked ok
Last night it threw the 3 blinks code and would not reset. I reinstalled the original (2007) circuit board and was able to light the stove manually again. Replaced the circuit board today with a new one no 3 blink code but still does not auto ignite.
Anyone have any thoughts on where else to look for what could be causing this?
 
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I would try a different brand of pellets.
 
I would recheck all areas where air can come in as disturbances in how the air flows can negatively impact ignition of the pellets. Remove and reinstall the plate for the fines box (don't just look at it or feel it, physically remove it). Before reinstalling, make sure there is no crud on the back side of that cover that would keep it from sealing.

Physically remove and reinstall the plate for the igniter area (just being cocked a little can cause issues - BTDT). While that plate is off, reach way back in under the igniter and see if there is a small dam of ash in front of where the air enters - had that happen too even though I though I was clearing that area at every cleaning. Even though the air wasn't cut off, it seemed to disrupt the air movement enough to cause an issue with lighting.

You said you cleared the air intake, but didn't mention if you checked to make sure the flapper moves freely.

And lastly, check your hopper door. Make sure it is closing and sealing. Even a small sliver of a pellet may cause issues without the stove thinking that there is an air leak.
 
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I did check the flapper and it does swing freely and the hopper door is clean and sealing
I will remove and inspect the cover for the fines box tomorrow AM when it is cooled down and also the plate for igniter, after that headed to town to get some new pellets.
Thanks guys, for the suggestions, I will update tomorrow with the findings.
 
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I removed the plate for the fines box and vacuumed out again this morning, the gasket on the plate is flattened out pretty bad, I vacuumed all of the fines off of the gasket and replaced it.
I pulled the cover plate for the ignitor clean out and cleaned both mating surfaces, removed the ignitor and cleaned all of the holes on the fire box again, reinstalled the ignitor but still will not ignite.
Headed to town to get different pellets and give that a try.
 
I may have spoken to soon, right before the end of the cycle I noticed smoke coming from the exhaust, the stove then shut itself down, I restarted it right away and in about 15 seconds I had fire.
Does that tell us anything?
 
So I ran the new board until tonight when I came in the house and the new board was showing the 2 blink code, unable to reset, replaced with the original board to get the fire going.
I ordered a new pressure switch and ESP cause I had both of those codes recently...and their cheap.
Any Ideas???
 
So I ran the new board until tonight when I came in the house and the new board was showing the 2 blink code, unable to reset, replaced with the original board to get the fire going.
I ordered a new pressure switch and ESP cause I had both of those codes recently...and their cheap.
Any Ideas???
I assume you set the dip switches on the new board properly? Also does it look like the stove puts enough pellets in the burn pot to cover the igniter holes? If it does not , you may need to adjust the “pre charge” setting on the dip switches.

Also where are these “new “ boards coming from and are they original Harman or the Amazon knock offs?
 
Yes the dip switches have been set and rechecked.
Ample pellets being put into the burn pot, nearly overflowing when it finishes the start cycle,
and yes these are new Harman boards.
 
It might help if you put a video up
 
You said you cleared the air intake, but didn't mention if you checked to make sure the flapper moves freely.
some good troubleshooting tips there.

What happens if the flapper is not moving freely?

I have an XXV that is having major starting problems and curious as to what having the flap not moving freely does?

Thanks!
 
This stove still isn't starting on auto. This is what i have done so far. Replaced the Ignitor with OEM (tried 3 different OEM ones) and cleaned the access cover plate, vacuumed ignitor area, replaced cover and tightened, good fit. Replaced the Combustion blower with OEM, Replaced the Circuit board with OEM (tried 3 different oem boards), Replaced the esp probe with OEM, Replaced the vacuum switch with OEM (this cured the 2 blink code), Replaced gasket on the fines box cover, vacuumed box and verified cover is installed correctly and tightened (when I put it back together the stove auto ignited one time but now back to not starting), Replaced the door gasket for the burn area, the lower gasket for the ash is in good condition. Cleaned and inspected the intake flapper,( it operates freely and opens when running). Cleaned the burn pot and all of the holes.
On the startup cycle (30 minutes or so) the burn pot is filling up with pellets, the ignitor light is on, there is heat and some of the pellets are charred but not enough heat to start, I had replaced the combustion blower because I had a lazy flame and black soot in the burn area but this wasn't the initial problem, the new blower did solve the lazy flame and soot issues.
Had a service tech out, verified my work and couldn't anything wrong.
I think I just about have a new stove but it does not auto ignite.
Who has any ideas?
 
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some good troubleshooting tips there.

What happens if the flapper is not moving freely?

I have an XXV that is having major starting problems and curious as to what having the flap not moving freely does?

Thanks!
The flapper needs to be able to open to allow intake air for combustion
 
some good troubleshooting tips there.

What happens if the flapper is not moving freely?

I have an XXV that is having major starting problems and curious as to what having the flap not moving freely does?

Thanks!

If the flapper doesn't move freely, it may not let enough air in for combustion to take place. Also, I've heard of some people using smaller pipe for their OAK so it goes on the inside of the stove's air intake instead of outside of it. If they push it in too far, it won't allow the flapper to move, which constricts air.
 
After you replaced the board and combustion blower did you test and adjust high /low draft. Too much or too little air could affect ignition.
Procedure is in attachment
 

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Good morning all. I have been a long time reader of this forum and decided to register today because I have been experiencing the same issue with my P-68 for over a year now. I have tried everything that has been discussed here with no resolution.
Currently I am running in room temp manual. One thing I have noticed is while in a maintenance burn the flame seems overly active and burns low and close to the auger. I believe there is an airflow issue where air is entering through the auger instead of the intended path.
I see also there is an updated ignitor cradle available so the design has changed for some reason. I may try this next as well as replacing my hopper gasket. The only other thing that comes to mind is the gasket between the hopper and feed weldment....
Rokey 199 if you're able to resolve this please post you're resolution here. I'll be sure to do the same.