Stove and thermostat seem to be in a bad relationship?

[PaulinOnt]

New here.
I've had my Quadrafire Santa Fe pellet stove for @ 6 years now and over the course of the last couple of years it seems that the thermostat and the stove have stopped speaking to each other. The problem is that after filling and firing up the stove and then having it run through a burn cycle and shut down when it heats the room, that it wont restart when the temperature drops back below the temperature set on the thermostat.
If I either drop the thermostat below the actual temperature and then turn it up to the desired temperature the stove kicks on. Also, if I hit the reset button it will start back up. I have tried a variety of alternate thermostats - digital/prorgramable, or basic, and they all fail to relight the stove when the temperature falls below the thermostat setting. No errors on the board.
Any advice greatly appreciated.

 

[kappel15]

Is there a possibility that there is not enough fire, so stove is shutting down due to lack of heat, or too much fire, that #2 snap disc is shutting down power to auger and shutting down that way. Then snap disc resets and you have to play with tstat or reset to run stove again? I would of said faulty connections with tstat wires but for the fact you can restart stove. Other option maybe is firepot thermocouple acting up, or not in firepot far enough or not touching inside end of cover. kap

 

[PaulinOnt]

Hey Kap, Thanks for the input.

I'm positive it has nothing to do with the start/run/shut-down cycle.
Here is the scenario - Say room is at 68 degrees and stove is not running, thermostat is set at 66 degrees.
I move the T-stat to 71 degrees and the stove starts, ignites, burns until room is 71 degrees, and shuts down.
Sometimes the stove will restart when the room temp falls below 71 degrees, and sometimes not.
When it doesn't, it just sits idle as though it doesn't know the thermostat is present.

It seems that the stove doesn't read the signal from the thermostat telling it that it's time to restart.
Could a bad thermocouple cause this and prevent the stove from restarting in this situation?

If so, then I agree that it's the most likely suspect since I haven't replaced the T-coupling since the stove was installed.

Of course I guess this is better than it not shutting down...I had that situation with an Enviro-mini about 8 years ago which is
why I upgraded to the Quad while I still had a house to heat!

 

[kappel15]

If the firepot thermocouple is not touching the inside end of the cover, or the cover is full of ash, it will have faulty readings, which could cause this. I have an 06 Santa Fe and am on the original firepot thermocouple, so age doesn't mean much. And another scenario. Have you seen the stove not start? I mean, it could have gone thru its cycle and then when It called for heat, it did fire up, but didn't get a fire going fast enough to satisfy the tcouple in reaching 200*, for fuel to start feeding again and went into a nuiscence shut down, which if you turned tstat up and down would work and also hitting the reset button. I have had this happen to me lots of times as I burn a mixture of corn and pellets. And if the pot is not cleaned enough and you get a buildup of ash, insulating the igniter slit, or the stove is cold. kap

 

[kappel15]

You can also use a small mirror and flashlight, and look in bottom of pot to see if there is a clinker blocking part of the igniter slit, which would cause the stove to not start sometimes. Also pull igniter and make sure housing is clear of any ash, blocking some of the heated air that starts the fire. And make sure all holes in firepot are clear, including the 4 small ones in pot floor and 4 small ones in front bottom of firepot. kap

 

[PaulinOnt]

Thanks Kap,
I will take the T-coupling out of the tube tonight and clean it to see if that's the cause.
Since I never have before that's a likely possibility, and good to know it could be the cause.
I just replaced the igniter coil a couple of weeks ago and the vent holes in the burn pot are clear
so I get flame rapidly on start up with minimal smoke and far less fly ash than before replacing it.
Paul

 

[kappel15]

And remember, it could just be misfires if you are not there to see what is going on. kap

 

[PaulinOnt]

Hey Kap,
You hit the nail on the head.
Last night I removed the T-coupling tube, tipped it up, and drained the ash from inside of it.
(The ash inside was more like the consistency of fine sand.)
I reinstalled the thermo-coupling and started up the stove.
It was been running through it's cycles flawlessly for @ 12 hours now.
Thanks so much!
Paul

 

[kappel15]

Glad you solved the problem. Stay warm. kap

 

[Former Farmer]

As usual - Kap to the rescue!

 

[PaulinOnt]

Actually Kap, it was you who solved the problem - I just turned the wrench.
Cheers!
Paul