I finally got the DuoTherm furnace taken out so I can inspect it. The
intake and exhaust pipes were both rusted through at the outer wall. They
weren't yet to the point of being unsafe but the day was near. The intake
and exhaust ports on the DuoTherm are side by side and separated by about 8
inches which is a lot different than the newer designs. The new Suburban
has the intake and exhaust ports close spaced and only one external cover
is required. This prompted me to make a best effort at refurbishing the
DuoTherm.
I disassembled the fire box and it is still sound so I cleaned it as best I
could and painted it with high temp paint. The original gaskets appeared to
be a fiberglass mat which fell out in small pieces. I intend to reassemble
it using High temp ultra copper rtv then reinstall it with new exhaust
pipes. I don't know the operating temp but the metal is galvanised so must
not be too hot. Maybe I'll stick in a thermocouple so I can document my
mistakes after the fact. I'll only use it maybe once or twice a year so
should get at least another ten years out of it.
My question is has anyone else been down this path and what are my other
options. This furnace is huge and takes a lot of valuable space. There's
not a lot of wall space where a catalytic heater could be mounted. There's
lots of ceiling available. Is it possible to put a catalytic heater up
there and either insulate it or used forced air to control the heat?
Another option would be a unit that mounts under the floor ot vents thru
the floor. Has anyone researched this?
As it sits, if no one throws a red flag I'll reinstall the DuoTherm for
now. If a new installation will require cutting fiberglass I should get to
a new configuration before I refurbish the exterior. Maybe I should bite
the bullet and do it now.
Talk to me
Dick Kennedy
'75 PB
intake and exhaust pipes were both rusted through at the outer wall. They
weren't yet to the point of being unsafe but the day was near. The intake
and exhaust ports on the DuoTherm are side by side and separated by about 8
inches which is a lot different than the newer designs. The new Suburban
has the intake and exhaust ports close spaced and only one external cover
is required. This prompted me to make a best effort at refurbishing the
DuoTherm.
I disassembled the fire box and it is still sound so I cleaned it as best I
could and painted it with high temp paint. The original gaskets appeared to
be a fiberglass mat which fell out in small pieces. I intend to reassemble
it using High temp ultra copper rtv then reinstall it with new exhaust
pipes. I don't know the operating temp but the metal is galvanised so must
not be too hot. Maybe I'll stick in a thermocouple so I can document my
mistakes after the fact. I'll only use it maybe once or twice a year so
should get at least another ten years out of it.
My question is has anyone else been down this path and what are my other
options. This furnace is huge and takes a lot of valuable space. There's
not a lot of wall space where a catalytic heater could be mounted. There's
lots of ceiling available. Is it possible to put a catalytic heater up
there and either insulate it or used forced air to control the heat?
Another option would be a unit that mounts under the floor ot vents thru
the floor. Has anyone researched this?
As it sits, if no one throws a red flag I'll reinstall the DuoTherm for
now. If a new installation will require cutting fiberglass I should get to
a new configuration before I refurbish the exterior. Maybe I should bite
the bullet and do it now.
Talk to me
Dick Kennedy
'75 PB
