Removal of furnace

[Stone Ridge]

I'm having trouble with the furnace on my "76. The fan has been making ratteling sounds for a while and yesterday It stopped igniting. As I understand it from other threads if the fan sn't producing enough "wind" to activate the sail switch, the gas will not flow and the burner won't light. I'd like to work on this and see what's going on. I know I'll have to replace the fan. My question is do I have to take out the kitchen cabinet (stove and all) to gaine access to the furnace?

[Mike Leary]

A pic would help; mine will slide out, leaving the enclosure where it is. You have a old-
style furnace, is it a Suburban? I have never seen (or heard) a fan go south; I'm thinking
motor or card or high limit switch or ignitor or gas valve or has not been cleaned, ever. Or, all
of the above.

[Lumatic]

On my 73 which had a Suburban furnace the furnace mechanical parts are mounted as a unit on a track which slides out of the furnace. As I remember the steps:
1. take off outside inlet /outlet cover
2. disconnect gas and electric lines
3. take of funace cover
4. remove 2 screws which hold furnace menchanical unit to cabinet
5. slide out furnace

It may not be worth fixing your furnace. Parts are difficult to find and most service techs will not work on furnaces of this vintage. New furnaces are just less of a hassle and you know they are safe. There are several threads on furnace replacement in the forums.

[Stone Ridge]

Thanks for the quick feedback. Mine is a Suburban. There is a wooden-cabinet support that is so close that I can't even open the "box that the ducts tie into, is it called the plenum? Should I be thinking that this is one of those Airstream "custom-built, non standerdized" designs? I'll take some pictures tommorow. Again, thanks for the feedback.

[Mike Leary]

Suburban did not change the housing for the newer NT30SP, so the change-out is not
too big a deal; I agree with Lumatic, bite the bullet and sleep well.

[Excella CM]

Take a good look. The furnace slides into a close fitting box which normally remains in-situ and into which the ducks are tied. It is held in by the center screw on the exhaust vent and one or two screws into the floor at the bottom front accessed after the front cover is removed.

[Mike Leary]

Get a "sniffer" or soap & water spray bottle when replacing.

[Lumatic]

Originally Posted by Stone Ridge

Mine is a Suburban. There is a wooden-cabinet support that is so close that I can't even open the "box that the ducts tie into, is it called the plenum? Should I be thinking that this is one of those Airstream "custom-built, non standerdized" designs?.

I can only speak on my 71 and 73. Hopefully yours is similar. On the top of the furnace cover in the front of the furnace is a latch to release the front. But you can't get at it. The service manual says cut a hole in the shelf above it so you can operate it. The furnace is set up as a downdraft. The plenum is the collection chamber at the bottom of the unit the ductwork comes out of.

[Stone Ridge]

Hi Lumatic,
Thanks for the interest and quick reply. Sunday I took some pictures but haven't had time to download them. Yes it's a Suburban and I've written down the info from the plate on the unit. I'll also send it along. Thanks again

[overlander63]

If your Sovereign is an International, you will probably have to remove the tambour slide near the floor in order to gain room to slide the furnace out.
You should have the gas line, some wires (mark them with tape labels so you know where they go), and 4 screws holding it inside. There will also be one or two screws on the outside of the trailer, you will need to remove th exhaust cover outside (4 screws) to access them.

[Stone Ridge]

Here are some photos of the 31', 1976 International Sovereign.The first was taken just after I removed an access door (hinged from the bottom)that ran the length of the cabinet. I eventually just ripped everything out that was below the counter top. The furnace is now sitting on the work bench ready for inspection. I know I'm sending more info so that I might enlarge my original question. Where is the best place to buy a replacement unit?

Depending on the time that's available to me I am estimating that this restoration will take at least 6mos. more.

Below is from the furnace info. plate

Suburban Manufacturing Company
Dayton, Tenn.

Direct Vent
Forced air furnace for installation in recreational Vehicles

Central Furnace

Model # IT32FCA
Code# MMJ
Input BTU per hour 30000
Bonnet Cap BTU per hour 24000
Manifold Pressure 11?
Orifice size 53
Type of Gas LP
Serial # 547791

[cameront120]

Call Palomino RV for a replacement. Great prices on water heaters, furnaces, etc.
1 800 297 5830

[Jim in Pima]

Fan Noise
The fan on my 1975 Sovereign sounded like ajet taking off, after removing the furnace I discovered the front bearing on the fan had worn to a point the squirrel cage fan was hitting the shroud. Also discovered heat exchanger had a big hole in it. So putting in a new unit.

[Stone Ridge]

I'd like to thank everyone for their thoughts and responses. Very helpful. I did replace the furnace and it works great! It was 14 degrees this weekend and I was nice and warm. If anyone needs to know how I did it let me know.