Harman P68 stopped igniting pellets

Hello
This P68 was working fine but the last time it lit it took a while and made a big puff of smoke when it did light up. Has anyone else seen this issue?
The big puff of smoke is called Pre-Ignition and that happened because the pellets did not light during the first startup cycle.
The start cycle works by filling the pot and then waiting for a fire. If no fire then the auger comes on and pushes more pellets into the pot and waits for a fire again. The reason the circuit board does this is if the stove completely ran out of pellets then a second charge would fill the burnpot and the empty auger chute.
In this case since the stove did not run dry and there was pellets in the auger chute it overflowed the burnpot causing the Pre~Ignition the last time and an overflowed burnpot this time.
To light the pellets properly there needs to be a good air flow and enough heat so the air flowing past the igniter under the burnpot has enough heated air to come through the holes and light the wood pellets on fire.
This is what happened in this case:
During startup the pellets got warm but did not light.
The burnpot was warm but may not be hot like it should be or the pellets may contain too much moisture and will not light,
Here is what we checked.
Air checks
Check under the burnpot that is was clear of ash.
Checked the air holes in the burnpot
What was found
There was no ash under the burnpot
However 2 of the holes were clogged with ash.
The holes were cleaned and some black carbon buildup was scraped and cleaned off.
Air checks - using test mode
The flapper in the air inlet pipe was opening and closing properly.
The combustion blower was blowing properly.
The air was flowing out the pellet venting.
Here is how we performed a Heat Check:
All pellets were removed from the hopper and in test mode all pellets were bled from the auger chute. A well known good fresh bag of dry pellets were added to the hopper.
The stove did fire up but the flame was unusually high because it took exactly 1o mins from turning on to stove mode to a fire.
Normally this should take 5-7 mins and no big flame because it should not overfeed and push a few pellets into the ash pan.
The cause can be one of 2 components here.
1. The igniter is weak
2. The igniter Triac on the circuit board is weak.
In this case the igniter was approximately 6.5 years old and the stove did have heavy winter use from beginning of Oct to end of May approximately 5-7 tons in Stove Mode or continuous burn.
Therefore the igniter was replaced and stove started
It took exactly 7 mins and no big fire
Then it went to run mode and the fire settled down and ran perfectly
Pic 1 - Out with the old igniter
Pic 2 - In with the new igniter
Pic 3 - It works!!

 

I did have a similar issue, but it was a heat disk that caused it not to light. It lit the second time, and the pot was full. Boom! Pretty cool, but it scared the crap out of me!

 

Yes it puts alot of pellets in the pot and boom! Also hard to find the failed component since it is a marginal failure and may test good! So thanks for that info and good work BHags!