Quadrafire CB1200 - no power to Auger motor

[Kmj]

I am stumped - Quadrafire CB1200. Call light comes on from thermostat, exhaust fan comes on, but no power to Auger (tested at molex connector) motor. Stove will not ignite hand fed pellets. Stove has been working fine all season. No change in pellets

What I’ve tested:
Cleaned Flue
Jumped vacuum switch
Jumped snap disc 2
Tested normally open/closed of each snap disc based off wiring schematic
Reset control board
Tested thermocouple under heat - got to 20MV before ending test.
Cleaned feed tube.
Checked/cleaned/tightened connections

The control board is showing an amber thermocouple diagnostic light. I’m not opposed to replacing, but it does not make sense to me as my understanding is the thermocouple is not involved in initial start up and it tested good.

Any help would be appreciated.

 

[johneh]

Does the Combustion fan come on when starting?
Welcome to the forum

 

[Kmj]

Does the Combustion fan come on when starting?

I believe so, I am not super experienced on stoves, is the combustion fan the one that creates pressure through the flue?

 

[johneh]

Correct
sucks air into the fire pot, over the heat exchanger and out the chimney
The stove will not light, drop pellets or run without this fan working

 

[Kmj]

I believe so, I am not super experienced on stoves, is the combustion fan the one that creates pressure through the flue?

There are 2 fans running. The one for the flue and I assume the combustion fan. The only one not running is the one that pushes the heat

 

[Kmj]

Correct
sucks air into the fire pot, over the heat exchanger and out the chimney
The stove will not light, drop pellets or run without this fan working

Confirmed it’s running. Removed plate below snap disc and saw fan running

 

[johneh]

Disconnect the thermostat and jump the wires
this bypasses the stat start stove work yes/no

 

[Kmj]

Disconnect the thermostat and jump the wires
this bypasses the stat start stove work yes/no

Jumped stat. No activity at Auger. Fans still came on.

 

[johneh]

Looks like the magic smoke escaped from the control box
But one last thing red button on snap disc # 3 Pushed down
Also with the vac switch jumped any power to the auger motor?

 

[Kmj]

Looks like the magic smoke escaped from the control box
But one last thing red button on snap disc # 3 Pushed down
Also with the vac switch jumped any power to the auger motor

I checked the button on snap disc 3, it appeared to be in, I pushed on it with a screwdriver, it did not go in any further. I also checked continuity across the spades and it was closed. Which according to the schematic is correct.

When I metered the auger motor I had the vac switch and snap disc 2 jumped, no power.

I thought control box as well, but the thermocouple diagnostic light on the box had me second guessing and I’d rather spend money on a 30 dollar part than 300 lol.

Truly appreciate you walking through this with me.

 

[johneh]

The vac switch is powered right from the control box.
So without being there to perform the tests all things point to the control box

 

[Kmj]

The vac switch is powered right from the control box.
So without being there to perform the tests all things point to the control box

Okay, I am going to short wire the thermocouple with a new one since I have it on hand, and then I’ll order a new box. Thanks again and hope you have a great holiday

 

[johneh]

Marry Christmas

 

[Ssyko]

CB1200 has a capacitor across the power leads, most times near the plug/connection for the auger. If it fails internally it will either reverse the auger or stop power to the auger

 

[Kmj]

CB1200 has a capacitor across the power leads, most times near the plug/connection for the auger. If it fails internally it will either reverse the auger or stop power to the auger

Yes. I saw the capacitor, I was measuring at the molex removing the capacitor from the equation

 

[Ssyko]

Gotta have the Cap, i dont remember the size, i keep a few in my tool bag. They are film caps

 

[Ssyko]

If you take out the control box, remove the screws pull the board out and hold up to a bright light you can see if the center of the board is burned out. Pantrol went to 3 layer boards so they are extreemly difficult to repair

Example:

 

[Kmj]

If you take out the control box, remove the screws pull the board out and hold up to a bright light you can see if the center of the board is burned out. Pantrol went to 3 layer boards so they are extreemly difficult to repair

Example:

Thanks for the photo! I ordered a thermocouple as that was the diagnostic LED I got, I was hoping to get lucky, but now I know I can confirm the board with this info

 

[Ssyko]

Just so you know the thermocouples have everything to do on the start up of the stove. It works as the proof of fire. As it starts the stove feeds pellets then ignite, as the stove builds a flame it heats the thermocouple to a set temp then when the board sees the temp/ voltage (yes the thermocouple makes voltage) it turns the auger back on to make a larger fire. When it reaches its set temp stove goes into run mode. 😎

 

[Kmj]

Just so you know the thermocouples have everything to do on the start up of the stove. It works as the proof of fire. As it starts the stove feeds pellets then ignite, as the stove builds a flame it heats the thermocouple to a set temp then when the board sees the temp/ voltage (yes the thermocouple makes voltage) it turns the auger back on to make a larger fire. When it reaches its set temp stove goes into run mode. 😎

Understood. I tested the thermocouple under heat load and measured voltage at the fork connectors. Stopped the test at 20MVDC. Are you saying a bad thermocouple will prevent the initial start up? My understanding is the thermocouple, as you said, proves fire and then helps regulate auger operation/pellet output. While the control board is giving me the diagnostic of thermocouple issue, testing it and the symptoms led me to believe that was not the problem. I am not an expert though on pellet stoves, im just pulling knowledge from some old HVAC experience, so happy to be wrong.

 

[johneh]

a bad thermocouple will prevent the initial start up

No, if the thermocoupler does not reach a set temp
The stove will shut down
Because the thermocouple does not see the voltage necessary
or in other words, see fire

 

[Kmj]

No, if the thermocoupler does not reach a set temp
The stove will shut down
Because the thermocouple does not see the voltage necessary
or in other words, see fire

Okay- so sounds like the board is the culprit. Appreciate the help.

 

[Ssyko]

thermocouple could be bad, changed it on mine before the board. but now the 3spd boards are cheaper now