25PDV Ignitor always on

[LoveTheDrake]

I have a 25PDV (mfg date 8/08). I bought the house last year, and the previous owner used it before that. Last winter, the igniter failed, and for the rest of the winter we lit the pellets manually. Today I installed a new igniter, cleaned out the stove, replaced gaskets etc. Then I plugged in the stove and walked away.

Later I walked by and noticed that the igniter was glowing red hot even though I had never turned on the stove. Not good. I pressed the ON button and then immediately hit the OFF button so it would go through the shut down sequence. After about an hour, the stove turned off, but the igniter is still glowing.

The control board doesn't appear to have any relays that could be stuck. Anyone have any ideas, or a wiring diagram with more detail than what is shown in the user manual?

Some more info:

1. Last winter, the fuse on the control board blew. I can't remember now if that was the same time the old igniter stopped working.
2. Toward the end of the winter, we were constantly tripping out on overtemp. There was a lot of ash in the exhaust pipe when I cleaned it out today.
3. Today I was reading about the a-b-c-d heating modes, which got me curious what my stove was set to. When I checked, it was set to "a", which seemed very odd. I set it to "c".

Thanks!

 

[LoveTheDrake]

In case anyone has the same problem, I was able to solve it after reading some other threads here. My suspicion was that when the old igniter failed, it burned out the controlling triac before the fuse blew. With a multimeter set on ohms, I found that two of the triac's legs were shorted together. I checked all the other triacs and did not find that on any other triac. I ordered a replacement from DigiKey (Digikey part number 497-3121-5-ND - $1.54) and installed it. That solved the problem.

 

[heat seeker]

Good troubleshooting! And thanks for sharing!