Community Forums

sometimers · 08-24-2012, 07:55 AM

woke up this morn furnace not kicking in ,havnt really checked anything just made sure we are not out of propane and we are not.had to turn thermostate right down and then back up to 70 fan comes on for 30 sec then turns off thats it .....any words of wisdom as where to start?

FURNACE SUBURBAN 35M BTU Thanks
Warren & Amy

nightriderrv · 08-24-2012, 08:01 AM

Will it even go through the lighting process, Fan starts run fo 15sec then trys to light

sometimers · 08-24-2012, 08:09 AM

it sounds like its waiting to light but doesnt and just shuts off seems like the same scenareo when ya have an empty propane tank,i know there is propane as the hotwater tank lights no problem

Thankyou
Warren & Amy

J Birder · 08-24-2012, 08:16 AM

Are you on battery or shore power? If you are on battery, when it gets low, the furnace fan slows down. At some point, it doesn't blow enough air to operate the sail switch and the furnace control, thinking there is no air flow, will not allow the furnace to light.

Joel

sometimers · 08-24-2012, 08:32 AM

Quote:

Originally Posted by J Birder

Are you on battery or shore power? If you are on battery, when it gets low, the furnace fan slows down. At some point, it doesn't blow enough air to operate the sail switch and the furnace control, thinking there is no air flow, will not allow the furnace to light.

Joel

Im On shore power,i also did check battery gauge says its right up my lp sensers all say there working so no smell or anything maybe somthing wrong with lp system to the furnace ??

Thanks
warren & Amy

nightriderrv · 08-24-2012, 03:16 PM

The low volts idea sounds likely have you checked with a meter to see if there is 13.6 with shore power on

sometimers · 08-25-2012, 05:41 AM

Quote:

Originally Posted by nightriderrv

The low volts idea sounds likely have you checked with a meter to see if there is 13.6 with shore power on

well i took the cover off the outside of the blew it out with air, blew out the intake exhaust pipes fan so on,still would not lite,as i could manually turn the switch on and off in furnace compartment, motor blower starts right away but no sign of it trying to light no ticking.so i tryed it again tapping on the exhaust pipe it lit so somthing loose maybe...i continued turning off and on and it has been working i just dont no what may have caused that

Thanks
Warren & Amy

George Z · 08-25-2012, 06:01 AM

Bad or stuck sail switch in furnace by blower. If switch does not activate when blower produces a wind stream the starting sequence will not happen. By banging you may have unstuck the switch. If it happens again you will probably have to remove the furnace and replace the switch.

nightriderrv · 08-25-2012, 06:58 AM

Mud dobber could had a nest started too and the tapping could have jarred it loose but any how it works good job!!!!

dmaxgus · 08-27-2012, 07:24 PM

Was it working during the night before it wouldn't come on in the morning? If so you may have a "High Limit" switch that went bad. When our Suburban furnace wouldn't work it was the limit switch. I had to remove the furnace and dismantle it partially to get to the limit switch. Once installed and placed back in the 5th wheel it worked as it should. Look in your book for the furnace and find the diagram that shows theroy of operation and trouble shooting. Should answer your question in there. May need to see a RV Tech for resolving it. Good luck.