Heater starts, then quits

[Ralph L. Fullenwider]

Hi Scott:

While many things can cause this problem, most commonly it is the return
air and the exhaust that are plugged up form mud daubers nests, they get in
form out side because the intake and exhaust were not covered with the
round screens.

The heat builds up in the plenum and the fresh intake air is limited or not
able to exhaust the heat and causes the limit switch to open shutting of
the gas valve which shuts down the flame on the beaver tail burner. The fan
will continue to run because the circuit going to the time delay relay is
interrupted. Having said that, if this limit switch is defective or "slow"
(it is a bi metal strip in a can, so to speak) or the time delay relay is
"slow" will cause this as well. Then there is the circuit board that can
cause this as well. Only testing the components will tell the tale.

To remove the unit from under the sofa, the front facia board mush come
off. Then with the lp valve tuned off, remove the LP line, then remove the
elbow and pipe going inside the heater through the outer case. Then with
power shut off, it must be un wired our un plugged ( if there is a plug).
The outer case does NOT need to be removed. There are 5 screws that hod the
heater unit in side the case, remove those and the until will slide out of
the case. In some cases, I have had to actually remove the sofa (not an
easy task) to slide the unit out. Many times the air intake and exhaust are
rusted and may need to be replaced as well. Be sure, when sliding the
heater back in, that the tubes align and slip at least 2 1/4 inches into
the exhaust tube, this prevents CO from entering the Coach.

Safe travels,

Ralph and Charolette Fullenwider
Ralph's RV Solutions, Duncan, Oklahoma

At 01:59 PM 10/20/2006 +0000, you wrote:
>The front propane heater in my FC starts up normally and will run for
>about 10 minutes or so, but then will just stop heating and blows cold
>air. This is happening well before the coach is warmed, so it is not
>the thermostat kicking it off, and the fan will continue to blow
>indefinately. Any ideas on a cause? Also, what is the easiest way to
>gain access to that unit?
>
>Scott Forman
>82 FC35RB
>Memphis
>
>