Heater starts, then quits

[Scott Forman]

Ralph,

Thanks for the wealth of info. Another question:

When I run my middle propane heater, I can smell "propane" inside the
coach. I put this in quotes because it isn't like a raw propane
smell from a regular leak, but rather like an exhaust smell or
combusted propane or something. Needless to say, I have not been
using this unit out of fear of CO or explosion. Does my description
make any sense to you and do you know what causes it?

Thanks

--- In WanderlodgeForum@yahoogroups.com, "Ralph L. Fullenwider"
wrote:
>
> 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
> >
> >
>