cb1200 help with diagnostics

Hi all, i'm hoping someone can help me solve this issue with a freestanding 6 year old cb1200.
When first plugged in, or first calling for heat, the auger spins exactly 2 times. I ruled out the auger motor because unplugged it receives 120v exactly 2 times, never more. There is no pellet jam. Homeowner had bypassed vacuum switch in hopes it would work but I tested it fine and it closes, so i reset it back to factory (no difference in bypass vs factory) Bypassing the vacuum switch also bypasses the hopper lid switch. so that is fine. Overtemp is not triggered. Fire back into hopper disc is not triggered. stove is clean. all discs seem to check out.Orange call light is on.
known issues - ceramic cover to thermocouple is cracked and missing a part - may or may not be good. can this shut down the auger motor immediately? I'm under the impression It should not, but i could be wrong. If it is "open circuit" causing the stove to think it is missing, will that shut the auger motor that quickly?
My only other guess is the control box. I don't want to replace this if its as simple as a defective thermocouple.
so in summary i'm down to
1. defective thermocouple
2. defective control box.

I did not open the control box but I did see a blue light flash when first plugged in.

Any other ideas for diag before I throw parts at it?


Thank you in advance for any and all ideas. I want to get my friend heat before our incoming cold snap.

Joe

 

https://downloads.hearthnhome.com/installmanuals/CLASSIC_BAY_1200_C_PELLET_STOVE_OWNER_7027_802.pdf

Page 23: "Call light on. No Fire. No fuel in fire pot."
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Diagnostic step 6: Check thermocouple is in good condition and plugged in properly.
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So yes, it sounds like the control board will not run w/ a defective or missing thermocouple (proof of fire).

Hope the info helps.

 

Thanks, im going to pick up a thermocouple today and see where I get, also the ceramic cover.

 

Good luck Joe, and hoping that fixes it up.

 

I had the same issue last heating season with my CB1200, the ceramic cover was pretty much warn through and that caused damage to the thermocouple. Hopefully the thermocouple gets you going! I learned my lesson and keep a cover and thermocouple on hand now.

 

Update - showed up with new thermocouple and she fired right up! I didn't think an open circuited thermocouple would kill the auger motor right off the get go, at least on a quad. I learned something new today. I thought it only affected operation at proof of fire and then again to turn on the convection.

Thanks to all of you once again for your amazing help. I was able to get heat back to 6 people since yesterday before tonight's bone chilling cold snap.

 

Oh its warm tonight! Got an englander 25-pah and and englander 25 pdvc going and its holding at 81 in here. both on setting 1. its a bit warm now but we're supposed to lose another 20 degrees tonight outside so i'll probably wake up to somewhere in the 70's


btw I just wanted to say man what a pain it is to thread a new thermocouple in a cb1200 without removing the burn pot. I did not want to wind up in a situation with a snapped bolt and gasket replacement so I did it the hard way. I think luck was on my side when it finally came out the tiny hole near the burn pot.