heater warms for 5-10 min. than blows cold air ???

[billybtalkin]

Let me begin by stating heater has not been used in about two years up until the last day or so. Having said that here lies my problem. When initially turning on propane heater ( 94' B190 ) it will cut on and warm air will blow. After about 5-10 minutes warm air will cease and cold air begin to blow out. This occurs regardless of thermostat setting ( high or low ) I also noticed while it is blowing warm air that I hear what sounds like a clicking sound or cycleing sound as though the burner is igniting ( this occurs while air is still warm mind you ) eventually the warm air ceases and again cold air blows. I would turn off at thermostat and turn back on short time later and heats up for a while and goes cool again. Is this a thermostat problem ? If so are there adjustments to such ? Lastly, what is the little on/off button for on the heater above the control board ? Thanks for any information, and Godspeed my fellow " B"s PS I do have propane and it is open and I have bled the lies by way off lighting 4 burners on stove for several minutes to insure no air in lines. Also propane side of ref., works fine...

[skater]

I'm thinking a problem with the furnace. There are a couple things that come to mind:

1. My parents had problems with both furnaces in their camper where in it would work correctly for one cycle, then it would just blow cold air when it cycled on again. I don't think that matches your problem, though - it sounds to me like the flame is going out in the middle of the cycle. (In their case, they had to replace the boards.)

2. Something is causing the flame to go out. Since you can hear the clicking sound, it sounds like the burner is trying to relight but it's not working. I'd suspect that the propane tubes are clogged. Spiders like propane so it's very possible one crawled in there and made a nest, for example - it happens often with gas grills. Make sure the gas is off, then you can use regular tools to disassemble and clean it, though I will admit I haven't done it.

Also, you do have the propane knob on all the way, right? Having it on only halfway might cause a problem like this, because the tank can't supply enough propane to the furnace.

[billybtalkin]

Thanks again to Skater for nudgeing me in the right direction on my heater problem. I removed and cleaned most of the contacts/terminals and blew with forced air through the reverse end of small vacume ( not compressed air as that may be to much force on delicate wiring/parts etc; ) along computer board and heater control unit and problem seems to have ceased. I left it running for about an hour and it worked as it is designed to including thermostat control. I believe as Skater suggested possibly a hinderance with gas flow caused by a number of things as it sat unused for sometime. Anyway, I am much obliged to this great help site and Skater in particular. Godspeed my fellow " B "s

[skater]

Thanks again to Skater for nudgeing me in the right direction on my heater problem. I removed and cleaned most of the contacts/terminals and blew with forced air through the reverse end of small vacume ( not compressed air as that may be to much force on delicate wiring/parts etc; ) along computer board and heater control unit and problem seems to have ceased. I left it running for about an hour and it worked as it is designed to including thermostat control. I believe as Skater suggested possibly a hinderance with gas flow caused by a number of things as it sat unused for sometime. Anyway, I am much obliged to this great help site and Skater in particular. Godspeed my fellow " B "s

Glad it worked! Stay warm.

(This reminds me, I need to test mine - I'm going camping in December, for work, and will need the furnace!)