Harman P35I exhaust doesn't shut down

[PELLET GOMBY]

I have a Harman P35I insert with exhaust fan not shutting down. The combustion light stays on also. This insert was purchased new in 2014 so was probably built in 2013. Here are a few possible clues that may be related. This last winter when turning the unit " OFF" it blew the stove fuse. I put a new fuse in and all seemed ok .
I did research on this and determined it could be a worn out potentiometer, which seems correct as it was a sloppy switch and the fuse blew when I turn it off with this switch. I recently replace the 3 pots with the "better" ones via EBAY purchase. I tried it out today to discover the fan runs continuously. More research mentioned it could be the ESP. I. happened to have one for backup incase it was ever needed. This is the one with red wires, same as the one that came with it. It did not solve the not shutting off issue. I don't know if replacing the pots caused this issue or if this issue was there a long time and I didn't notice it.
I found a thread that mentioned there is a #4 location TRIAC that is a common cause of the fan not shutting off, but mentions the red light is not on . Mine is on.
Any thoughts on this " faulty triac being a cause of the not shutting down ? If it could be I would replace it before having to install a new board. Anyone else had this issue and had a resolve ? Thoughts appreciated and many Thanks !

 

[bogieb]

Before throwing more money at it, try this:

Open the fire chamber door and put it in test mode. The exhaust fan should start up with the distribution fan going on occasionally. After 30-40 seconds, close the fire chamber door and latch it. Does it start feeding pellets (don't worry, the lighter won't be active so the pellets won't start burning)?

If pellets start feeding, then turn it off of "test" and see if the exhaust shuts off.

If pellets don't start feeding or the exhaust doesn't shut off after taking it off test, then you may have an air leak that is enough to keep that exhaust fan on. I would check to make sure all doors are fully closed - physically open and close them. Also check the hopper lid mating surface to make sure a piece of a pellet isn't keeping it from completely sealing (although you will be able to "close" it without too much effort).

Also, with the stove turned off, unplug it, then remove the fines cover, clean the gasket and replace the cover.

Try the test again. If the exhaust fan still won't go off, check the seals for the fire chamber door and ash pan door. They may be old enough to stay compressed and allow air in.

After that, I got nothing and others are way more suited to answering technical questions than I am.