Re: [VAL] Replacement Furnaces

["Mark" <mark@xxxxxxxxxxxxx>]

The innards of the NT furnace series are all interchangeable.  The good part
about that is that the original furnace cabinet is very likely glued or
siliconed into the outside wall.  To remove the cabinet, then replace it
with identical one, would be a waste of time, and probably break the seal
forever, unless he really wants to make a lot of work for himself to have a
shiny new box, which nobody will see.

There are a lot of things on our rigs which can kill us.  One of the most
insideous is the problem he has right now:  a leaky heat exchanger.  It's
dumping evil gasses, and distributing them throughout his entire rig via the
air handler and ductwork (assuming it's all intact).

There have, for many months, been brand new Suburban NT furnaces on
ebay...complete with factory warranty and free shipping...being offered by
RV dealers who are either overstocked, or bought a truckload to re-sell.  If
their feedback is good, I doubt there would be a problem.  If a seller had
ANY negatives, I'd go back through his feedback and read every one.

If your local dealer can supply one for not much more, you might want to
make a few points with him, and buy it locally.  If you have the nerve, you
might show him how much you can get it for on ebay, and let him make an
offer...might tick him off though...your call!

I believe the new units have stainless heat exchangers, instead of the older
blue steel ones...ought to last a LONG time.  Having just gone through my
own heater repair, here are a few tips:


Remove the chrome outside vent cover (if  your unit has a rust problem, that
cover may very well stick to the furnace in/outlets, making removal a real
booger.  When you re-install, it can hang up the final shove to get
everything back in place.  Best to take it out of the loop, clean it up, and
re-seal it when you're done, unless you get a new one with the new
furnace...I think you do)

Shut off the gas, and disconnect it from the furnace.

Remove any pipe fittings which run through the hole in the cabinet.

Disconnect the three-wire, plastic connector, right near the gas pipe.  (It
will have the little tabs you'll have to squeeze to release it).

The guts are now ready to slide out.  Chances are, they may well be stuck to
the bottom of the cabinet...rust.  You might want to shoot rust breaking
chemicals (WD?) in there, between the bottom pan of the guts and the bottom
of the cabinet.

However, since your unit is shot anyway, you could probably wrap a rope
around the gas pipe (inside the cabinet) and use that, and some sweat, to
break it loose, then slide everything straight out...it's not as bad as you
think, once the rust seal is broken.  Wear gloves...it's easy to smack your
fingers and knock the bark off if things let go all of a sudden!  My scab is
almost healed....

And be sure to check your duct flanges...sometimes the flex duct is screwed
to the flange with a long screw, and the pointed end of the screw protrudes
into the area needed to let the internals slide out.  This is especially a
problem if it's on the bottom right side (under the gas line)...a screw
sticking out there can grab the cardboard cover for the control circuit
board, and tear it up.  It can also snatch wires and mess with them, too.
If you find that to be the case (protruding screw), slide the flange (with
the flex intact) out of it's guides, and push it to the side to get it out
of the way.

After all is said and done, you might want to sell your good parts on ebay.
The gas valve, relay, circuit board, sail switch, etc. ALL have value to
somebody, if nothing else, for backup parts.  If you're heater fired and ran
fine, but leaked fire, it would imply your other parts are working, and
could be a real boon to somebody.  If your circuit board is a 'Dinosaur'
brand, it's a replacement, and a better unit than the original.

Good luck,

Mark