Atwood Furnace Hard Lockout

**Gary RVRoamer** · 03-15-2008, 07:20 AM

I've been reading the Atwood furnace manuals to help somebody out (successful!) but came across something I don't know the answer to. Am hoping that somebody here (RV Wizard Mike???) can provide the answer - just in case I ever need to know it!

I have an 8500-IV two stage furnace and it includes a diagnostic light on one of the two circuit boards that can flash 5 different codes. Three of the codes are "soft" lock-outs that can be reset by cycling the thermostat off & back on again. Two others, code 4 (Stuck sail switch) and code 5 (Module failure) are termed "hard" lock-outs and no reset procedure is given in the operator manual. Obviously these conditions would have to be repaired before the furnace will work again, but odds are I would be able to do that myself, even if I had to replace the module (circuit board?).

My question is, what is the reset procedure for a "hard" lock-out???

Inquiring minds want to know!

**Gary RVRoamer** · 03-15-2008, 07:20 AM

I've been reading the Atwood furnace manuals to help somebody out (successful!) but came across something I don't know the answer to. Am hoping that somebody here (RV Wizard Mike???) can provide the answer - just in case I ever need to know it!

I have an 8500-IV two stage furnace and it includes a diagnostic light on one of the two circuit boards that can flash 5 different codes. Three of the codes are "soft" lock-outs that can be reset by cycling the thermostat off & back on again. Two others, code 4 (Stuck sail switch) and code 5 (Module failure) are termed "hard" lock-outs and no reset procedure is given in the operator manual. Obviously these conditions would have to be repaired before the furnace will work again, but odds are I would be able to do that myself, even if I had to replace the module (circuit board?).

My question is, what is the reset procedure for a "hard" lock-out???

Inquiring minds want to know!

**RV Wizard** · 03-16-2008, 01:39 AM

Gary, I will have to access this technical data for the answer. I know that if the control module were to fail; the new one will not need reseting.

Will get back to you later on the sail switch repair and rest of this hard lock out.

**Gary RVRoamer** · 03-16-2008, 03:39 AM

Thanks, Mike. No rush - this is just a "what if".
Have you ever heard of a stuck sail switch? I haven't, but I guess it must happen if they made a code for it.

NYMoose "Lenny" · 03-18-2008, 03:09 AM

Gary,
I have heard of and seen a stuck sail switch. I was working on a coach where he was using it as a full time home. He had a dog that shedded quite a bit and he was a heavey smoker. There was nicotine buildup everywhere. When the furnace was pulled apart, it was like syrup and dog hair on the sail switch and all the connections, I have to admit, I was so glad I do not smoke. Either way, a new sail switch put in the other one was gummed up real bad with the hair a nicotine, and everything worked fine.