Cab 50 feed problem

[Joezeppy]

We bought a used 2014 cab 50 last winter. It ran good most of the winter, near the end it seemed the thermocouple was acting up. It would stop feeding and shut off. I could push the thermocouple in a little bit and restart and it would run fine again. This year it happened again but I couldn't get it to keep feeding anymore. I replaced the thermocouple, the old one was frayed from rubbing against the bottom. Now it won't feed passed startup except if I hit the rest button. I've watched the control box and the call light is on, but the green light does not come on.
How do I nail down what the root cause would be?
Thanks

 

[jzm2cc]

There is potential for reverse polarity on the new thermocouple if it's an aftermarket item, seen that issue several times. You'll never get a green or red LED status if that is the case. If you can compare it to the old thermocouple with a multi- meter, try it. Assume thermocouple is inserted fully into ceramic cap. Without the green LED status the stove will not feed additional pellets beyond the initial startup amount.

 

[Joezeppy]

There is potential for reverse polarity on the new thermocouple if it's an aftermarket item, seen that issue several times. You'll never get a green or red LED status if that is the case. If you can compare it to the old thermocouple with a multi- meter, try it. Assume thermocouple is inserted fully into ceramic cap. Without the green LED status the stove will not feed additional pellets beyond the initial startup amount.

The new thermocouple reads .4 ohms both ways. When I tested for mvolts after startup, the best I could get was 13. That was after cycling the reset once to get temp up in fire pot

 

[Joezeppy]

Anyone else that might have an answer or idea I can try? What could I check to eliminate the control box?
Thanks

 

[kenmal]

Anyone else that might have an answer or idea I can try? What could I check to eliminate the control box?
Thanks

I have had similar issue like that with my cab50, After going thru every thing it was the igniter causing it, Every two years I have to replace it.

 

[Mt Bob]

What jzm was saying, switch the 2 wires of the probe at the connector where it plugs into the control board. Yes it makes a difference, and many were sold assembled wrong.

 

[jzm2cc]

13mV is more than enough for green LED and Red. I'd try reversing the polarity on the thermocouple leads to see if you get green LED to come on during next start up attempt.

 

[Joezeppy]

13mV is more than enough for green LED and Red. I'd try reversing the polarity on the thermocouple leads to see if you get green LED to come on during next start up attempt.

You were right, I created a set of jumpers for the thermocouple, had to hit reset once, and the green light came on. It's been running correctly since.
Thank you

 

[jzm2cc]

Glad it worked out Joezeppy. Seems to be a rash of improperly assembled thermocouples out there.

 

[Mt Bob]

Glad it worked out Joezeppy. Seems to be a rash of improperly assembled thermocouples out there.

Yep, how many years now?4-5?