Community Forums

georgetown350 · 04-21-2007, 05:02 PM

Furnace works fine on first cycle but after shutting off as it should, it doesn't cycle back on until we are frozen. I had to wake up every hour and manually switch the furnace on at the thermostat. Anyone had this problem? Wondering if duo therm thermostat is faulty or maybe the problem lies in the furnace it self. Motorhome is one year old.

Thanks

Steve

georgetown350 · 04-21-2007, 05:02 PM

Furnace works fine on first cycle but after shutting off as it should, it doesn't cycle back on until we are frozen. I had to wake up every hour and manually switch the furnace on at the thermostat. Anyone had this problem? Wondering if duo therm thermostat is faulty or maybe the problem lies in the furnace it self. Motorhome is one year old.

Thanks

Steve

RV Wizard · 04-22-2007, 12:41 AM

Steve, the problem could be either the T'stat of the furnace. Some more diagnosing will need to be done. When you turn the furnace on, does it ignite on the first spark off ignitor? Have someone turn it on as you listen outside by the vents. If it does then I would think you are having a control problem. If not then it could be in the furnace or even the battery supply. Make sure you have good 12 volt first. Let us know what you find.

georgetown350 · 04-22-2007, 05:33 AM

Thankyou I will try that tonight. I will say that when the blower comes on that heat follows shortly after through the vents. After the first cycle ( when we are frozen ) I tried raising the thermostat temp up all the way. This did not trigger the furnace to come on but when lowering the thermostat down below room temp, and back up again, it would come on. Or if I simply switched thermostat off and then back on it would trigger the furnace to come on. I will report back if the furnace ignites on the first try asap.

Thankyou for the reply.

Steve

Bushman512003 · 04-22-2007, 08:11 PM

I had the stat.as You have and changed out to a digital one and it works fine now I have changed out 3 units so far and all worked fine..Just buy a cheep one at w-mart about $20.00 they use 1 or 2 AA batt. change them every year the Motor Home has air and heat also 2speed fan so I had to add a small switch for the high low fan also.Not hard to swap out.Ken Ledger has the info.on His Home page and is always there to help at RV.NET..Need more info.P.M. Me Bushman

georgetown350 · 04-25-2007, 12:43 PM

Furnace does fire up on the first try. Actually in my driveway the furnace was working properly last night so go figure. I will continue testing it until it acts up again. ps. I have one of those cheap duo therm t stats and I cant figure out how to get it open.

Thanks for the replies

Steve

RV Wizard · 04-26-2007, 02:33 AM

Steve the front cover should pop off; may need a knife blade to help seperate cover from base.

georgetown350 · 04-26-2007, 03:06 PM

Thankyou. I will go get a knife right now and get to it.

Steve

Periscope Man · 04-30-2007, 07:29 AM

Steve, the T-Stat is just an on/off switch, if the furnace blower comes on, the T-Stat is doing it's job (calling for heat). If the furnace does not ignite than you have a problem with the furnace, could be several things, if the blower is not up to the correct speed than the sail switch will not activate and you won't get any heat, the circuit board may be bad or the contacts may be dirty.

SEMO Mike · 04-30-2007, 12:32 PM

I had a similar problem and took it up with a vendor at an RV rally. He popped the top off the thermostat and blew the dirt out. It has worked fine every since. He said you need to do that periodically. MIKE

georgetown350 · 05-01-2007, 12:10 PM

Thankyou for the replies. Hope its just a little dirt in the t stat and not a problem with the furnace.

Steve

Flintstones Adventurer · 05-02-2007, 05:11 AM

Steve I wouldn't risk another cold night with that tstat. It sure sounds like the bimetal in your stat is weak and not moving as it should with the temperature changes. Thermostats are a cheap fix, try that first.

Good Luck and let us all know the outcome.

georgetown350 · 05-02-2007, 03:57 PM

Thankyou I will stay on top of it although I may not need the furnace until the fall now.
I think I have another year of warranty left which should help.
thanks again

Steve