Atwood Furnace & DuoTherm Comfort Control issue

[Daniel LOUIS]

I own a 2004 AS Classic equipped with an Atwood 8525 IV gas furnace linked to a Duotherm Comfort Control, both of which have worked flawlessly until this season. The Comfort Control usually controls the fan, the air conditioning, the heat pump and the gas furnace. As of now, it only controls the first three and does not "see" (i.e. read) the furnace whatsoever. I've done a reset of the Comfort Control but to no avail. I've also cleaned accessible parts of the furnace and checked terminals on its circuit board. Nothing. I can't seem to find the circuit breaker. Or could it possibly be the sail switch ? (Where/how do you check these ?) Any other suggestions ? Thanks !

[daveswenson]

There is no circuit breaker for the furnace, since it is a 12v dc controlled propane operated appliance. Have you checked the fuses?

[Daniel LOUIS]

Thanks for the information. I've been unable to find the fuses as well ...

[Daniel LOUIS]

I have however located the bus bar under the front goucho. (see photo)

[mrfixit51]

Those are self resetting 12v breakers. If they trip and do not reset themselves, you have something going to ground. Use a test light to check for the one that is tripped, if it is. Could also be a wire broke at the 12v appliance.

[guskmg]

If Airstream did not change the DC circuit breakers after yours was built my 2006 has resettable breakers. Not automatic. They look the same. Just look real close at one end of the breaker and find the little black stud. If the breaker is tripped the stud will be extended some. Just reset it. Don't keep doing this, find the short. BTW, automatic reseting circuit breakers can be a severe fire hazard. I would avoid them at all costs. I nearly lost a TV and TT because of them. The problem is they reset automatically. With an intermittent rapidly cycling short they will eventually fail, overheat and burn. Think engine compartment fire going down a mountain grade at 65 mph. And the culprit was an automatic resetting circuit breaker for the TT battery compartment.
guskmg

[mrfixit51]

My experience is the automatic will not reset if the ground problem persist. They are bimetal, so when the circuit makes them hot they stay open. If left for to long they fail open. I always used quality ones for 45 yrs, never experienced a fire or major heating. Now cheap designed ones could become a problem. Manually resetting any breaker can also be a problem if exaggerated and forced.

[Daniel LOUIS]

Thanks for the input. I'll take it to a qualified technician to have him take a look at it. Who knows, the problem might also not be fuse/breaker related as well.