Heater starts, then quits

[Scott Forman]

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

[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
>
>

[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
> >
> >
>

[Ralph L. Fullenwider]

Scott:

Check to see if the exhaust tube is rusted through. Also the fire box or
plenum could very well have a split or pin hole in it. It needs to be
pulled as well and fully checked. Many parts are still out there for the
older units, but if the fire box has a problem, put a now heater in with a
new exhaust and intake assy on the out side.

Ralph

At 03:34 PM 10/20/2006 +0000, you wrote:
>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
> > >
> > >
> >
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>

Safe travels,

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

[Troy Tikalsky]

Replace the thermocoupler, this senses the flame and will shut down the gas flow
and are problematic, looks like a metal probe near the flame. No easy way to get
at, remove the whole unit.

Troy Tikalsky
1986 Newell


----- Original Message -----
From: Scott Forman
To: WanderlodgeForum@yahoogroups.com
Sent: Friday, October 20, 2006 8:59 AM
Subject: [WanderlodgeForum] Heater starts, then quits


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





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