New here and new to 5th wheel. Heating problem..

[Guvner]

I bought a used 2000 Keystone Montana. Being an HVAC repairman I was simply shocked when my "new to me" furnace showed an intermittant problem. Unlike your home furnace everything is pretty hidden from you and it's a little hard to see the sequence of operation so you can see what's up. After it doesn't run for a while it starts up on demand but after running a while the Suburban furnace quits and leave the fan running after I'm supposing 3 attempts to start before locking out. Bad idea to leave the fan on but it's there furnace. Anyway without the benefit of being able to view the sequence of operation I'm left assuming the board has a problem since if the sensor was dirty it wouldn't come back to life after cooling down. I smell no gas and here no ticking on a restart before letting it cool down again and the limit isn't open that I can get a meter to.

Any experience with this problem? I researched the web and found a Dinosaur board that supposedly is a replacement for it that eliminates the fan continuing to run after lockout and also does a retry after an hour. Any advice on Dinosaur or faults in my troubleshooting? I'm thinking there may be a cold solder joint that could be easily fixed but the fan being left on isn't such a great system.

Thanks.. Gary

[7.3Ford]

Gary,

More than likely it is the gas supply line. The current LP bottles and pig tails have safety features that shutdown the flow to hardly anything if they think there is a leak. They always seem to think there is a leak if you ask me. Check the owners manual on the procedure to clear them. Try the other tank. Make sure the selector value is green.

[Guvner]

I left the burner on to the stove watching for a problem. Wouldn't that show me a problem? Thanks for the input in any case. Something new to ponder and it sounds like you've been there before.

Thanks.. Gary

[alandaudrey]

Gary, it seems to me this topic was recently discussed on the forum. You might want to do a search in the archives.

If I remember correctly people were having a similar problem to yours and the problem seemed to be the hole in the wall behind the thermostat allowing too much heat to be concentrated on the sensing element and causing the furnace to shut down early.

[Carl n Susan]

Here is a link to an older topic which describes the sequence of events when the heater starts up.

http://www.montanaowners.com/forums/showthread.php?t=13721&whichpage=2&SearchTerms=hea ter,sequence

I remember a more recent thread (maybe by Oz) with another (and better) description of the start-up sequence. I just can't find it right now.

[Guvner]

I believe that was one of the ones I followed and you can bypass the thermostat quickly eliminating that problem and I did. I haven't checked into 12 volt thermostats but I'm assuming they have a heat anticipator which I'd bet was at the root of that problem. But never seeing the specs on a 12 volt thermostat I really don't know. In any case I bypassed the thermostat and it didn't help my problem.

Thanks... Gary

[ole dude]

Many of these units have a sail switch in the supply air side to prove the fan is running and moving air, this switch can some times be a problem.

[8.1al]

Gary,
I sent you an email with a troubleshooting guide. If you need a board the Dinosaurs are very good in fact many feel they are better than the factory boards