Thermostat for Quadra-Fire Classic Bay 1200i

That's a bummer. Now I'm thinking it's not the thermostat. But you said the other one worked until the kids broke it...

I wonder if there is some sort of firmware update for the control box. Did a dealer install it ?

I'm not sure what to tell you, I'm still pretty new at this.

Sounds like an issue with the thermocouple and not thermostat to me. Try taking the cover off and cleaning out the ash and be sure the wires are touching the end of the cover.

Of it cycled twice last night and worked I don't see how it can be the thermostat.

What exactly happens whem the thermostat clicks and starts calling for heat again? Does the stove feed pellets and not ignite or just nothing at all? On the initial startup do you have to press the reset button?

Hey Gato,

You can try bypassing the thermostat entirely by connecting a jumper wire between the thermostat terminals at the back of the stove - where the two thermostat wires normally connect - UNPLUG of course before you do. Then plug the stove back in and see if it completes a normal start-up sequence. If it does, then the problem is with the thermostat or the stat wires. If it doesn't go through a normal start-up with the T-stat jumpered then it is something else, or in addition to the T-stat, causing the issue.

You shouldn't have to glue the ceramic TC (thermo-couple) cover on with anything - as long as it isn't angled down into the fie pot it should be able to maintain contact with the solder blob at the end of the TC wires. If the thermo-couple is bad you should see an amber colored light in your control box - less likely if you recently replaced the TC, unless maybe the connections to the wiring harness are bad.

Try the above and post back on what rex asked ie does it feed pellets on the failed start-up cycle.

DK

Gato13 said:

Edit: Since I leave for work early in the A.M., let's just say that DMKNLD suggestion works; is it OK to leave like that (The jumper connected)? or it will cause some damage to something? or just the thermostat "feature" won't work and will keep cycling over and over?

Thanks

Click to expand...

Yeh, that's OK to temporarily run your stove that way. Bypassing the thermostat with a jumper just keeps the 'call for heat' circuit on full time instead of cycling the stove on and off via the thermostat when the set temps are reached. That's essentially how pellet stoves work that don't have thermostats, and instead use an on / off switch.

The only hassle when the t-stat is jumpered is turning it off, given that a Quad that doesn't have an on / off switch. Unplugging it will stop your combustion blower and thus the ability to clear the firebox of smoke. The easiest way to let the stove shut down is to open the hopper lid if you have a newer model that has a hopper switch, and that will shut down the auger feed. If no hopper lid switch, you can remove one of the t-stat jumper wires. But if it's easier on your CB to access the vacuum switch than it is to remove one of the t-stat jumper wires, you could instead pull off the vacuum hose at the vac switch end, which will shut down the vacuum circuit, that will then shut down the auger feed and let the stove shut down / clear the firebox of smoke. Once the combustion fan shuts down you can unplug the stove and then hook back up the vacuum hose or the t-stat jumper. If you want to start it up again with the t-stat jumpered you'll need to hit the reset after plugging it in.

Good luck! You'll get it figured out ! Keep us posted how things play out. DK

Yep, sounds like it's not your t-stat. Sounds like you get the normal start-up with the green and then red lights - which indicates your thermo-couple is working OK, then it quits feeding pellets at some point after that, correct ?

The process of elimination in pellet stove troubleshooting starts with being sure the exhaust pathway is clear of fly ash from the fire pot holes to the termination vent. Then the next step is to make sure there's no air leaks causing a vacuum circuit issue, which can often cause 'mystery shut downs' like you're having.

Are your door seals good ? Do the 'dollar bill' test all around it to make sure there is some resistance to pulling out the bill or piece of paper. You're sure your fire pot clean out 'trap door' is closing fully and is not hanging down more than a dimes width on the non-hinge side ?

Sawdust build-up can cause a partial obstruction in the vacuum hose, that goes from vacuum switch on the lower back of the stove to a nipple on the upper back side the auger tube. The vacuum tubing and / or the nipple can get blocked at the top of the auger, particularly if you're burning especially dusty pellets. You can clear it by disconnecting the vac hose at the switch end and blowing through it with Dust Off type canned air, or just blowing it clear with your mouth will work too.

It's best to take the vac hose completely off and make sure the auger tube nipple is clear by poking a toothpick or straightened paper clip into it. You can also check for cracks in the vac hose, most commonly in the auger connection end where it gets exposed to more heat. If the tubing end is cracked or doesn't fit snugly on the nipple you can just trim the hose end off a bit.

Vibration and dust build-up over time can compromise the electrical circuit contacts between your control box and the junction box. With the stove UNPLUGGED (standard disclaimer), try removing then re-seating the control box. Is your control box the original one, or is it the upgraded clear one ?

Check the above stuff and then post back. If no change, the next thing to do is to temporarily bypass your vacuum switch to rule out a bad vac switch, which isn't too hard to do but takes a little more electrical awareness.

Good luck ! DK

OK, that's a good breakthrough - yes, warm is good ! So that sounds like a feed rate related issue, where the high stove setting gives enough fuel feed to keep the flame burning consistently, but not on the medium or low stove settings. When the feed rate is set correctly on the high setting it should have a flame height that is 4-6" above the fire pot. From your pics it's a little hard to tell but it looks like your flame height is a good bit less than that. So you should open your feed gate up in small increments, wait about 10 mins or so to see how the flame corresponds, then open it up a bit more again as needed. The flame height will ebb and surge some, but should be generally in the 4 - 6" range on the high setting. Then that feed rate setting is right for the medium and low settings on the stove as well. The flame should be brisk and yellow to white in color.

The other feed related cause could be sawdust and fine pellet pieces built up at the bottom of the hopper, which can keep the regular sized pellets from getting picked up by the auger screw. Do you periodically vacuum out those pellet 'fines' that collect there ? If not, that can cause an insufficient amount of pellets to be fed to the fire pot. If the bottom of the auger tube is clear of fines, you could have a partial pellet 'bridge' at the top of the auger, particularly if the pellets you're burning are consistently longer than an inch and a quarter or so in length. If you have a small mirror you can hold it at the bottom of the pellet drop chute, above the fire pot, and shine a flashlight beam off the mirror to see if there are any pellets obstructing the top of the chute. Or you can take a straightened out coat hanger or long handled screw driver and poke around at the top of the drop chute to break up any 'bridged' pellets that might be partially blocking the pellet feed.

A couple other thoughts. Did you clean the stove glass before you ran the stove on high, or was it dirty like that before? The reason I'm asking is that your glass shouldn't get that dirty overnight, without some other air flow leak or a vent restriction issue that would cause allot of sooty ash to be deposited on the glass. Did you clean the vent all the way to its termination with a vent brush to make sure it is clear ? Lastly, what pellet brand are you burning? A stove and the venting can be perfectly clean, with the correct feed rate and no air leaks, and the stove can still burn crappy with poor quality pellets. After my 1st burn season, when I mistakenly bought 4 tons of 'dirt in a bag' pellets, I can speak to that personally.

Update back again after you've checked the above stuff. It must be cold for you guys in NY like it is here in ME, so having a warm house on New Year's eve is a good resolution to make ! Cheers, DK