'$1,100. for combustion chamber 98 Suncruiser. Too much??'

ALL these replies and WITHOUT THE MODEL NUMBER, NOBODY can give good accurate responses or help. Doug

islandlady wrote:
Suburban furnace will ignite then cut off and starts blowing cold air. Service tech says need combustion chamber. Also, exhaust pipe is rusted out. Is $1,100 a reasonable price for a replacement?

Find a new tech fast!!!!

Ours did that and we needed a new circuit board. I'd get the 2nd opinion for sure.

A new Suburban RV furnace is somewhere in the $900.00 range. Add installation and potential modifications to existing gas lines and power supplies and $1100.00 is not out of line. If you shop around and install the furnace yourself you may be able to save $300.00.
Randy

I should also mention that the furnace (mounted in the rear of my MH) is quite easy to remove. After doing it a couple of times, it was about a 5 minute job.

I would be surprised if it is the combustion chamber itself unless it's rusted out. I don't understand why, if the combustion chamber was rusted through, it would shut off. I also doubt that it is the sail switch as it won't light at all if that has failed.

Does the unit blow hot air for a little while before the cold air starts?

I chased my furnace (and myself) around the mulberry bush a few times before solving my problem.

Read about my travails below.



After a month of tests, ordering parts, installing them when they arrived, and then more testing because the furnace still didn't work, it is now fixed.

Short Version:

One of the coils on the LP valve would short out after a few minutes of operation and shut the LP off.

Long Version:

I figured the high temp limit switch was bad or the fan motor wasn't putting out enough air volume. I replaced the switch and no change.

The motor was a little noisy, so I checked that. The commutator was worn but the shop I took it to couldn't/wouldn't fix it------they said the brush springs were also weak, and they couldn't find replacements. So I bought a new motor. That didn't fix it either. At least the motor is now quiet.

Called Suburban and they suggested checking the voltage at the gas valve. It started out at 12 volts but would drop to zero when the fire went out. Something was evidently, they said, telling the circuit board to shut off the gas valve or the board was bad. I jumpered the high temp switch and the sail switch and checked for voltage again. Again, the voltage dropped to zero when the fire went out. So I ordered a new circuit board. That didn't fix it either.

The only other thing that might be telling the circuit board to cut off the gas valve is the flame sensor/ignitor. So I ordered a new flame sensor/ignitor. That didn't fix it either.

Then I went back to the gas valve solenoids and spliced in a separate feed cable that I hooked up to a 2 amp battery charger. I hooked the charger up to it once the fire was started and monitored the voltage again. The fire went out and the voltage dropped from 12 volts to 7-8 volts-----so the coil must be shorting out. With just the minimal current from the circuit board, the voltage would drop to zero, but the extra current from the battery charger was enough to show that it wasn't the board cutting if off.

New gas valve and it now works.


If anyone needs a good used circuit board or ignitor/flame sensor, PM me.

Don't think a 98 is obsolete. Just get a new one.

Sounds like you need a new sail switch..... get that second opinion! Have you actually seen the rusted pipe?

First, I would get a second opinion. Then, I would sit and think about it for awhile. I bet you can figure a solution to this for a lot less. Sorry, it just doesn't sound like a combustion chamber problem

Ken Gasbarri

your subject title..threw me until i read the post

just say "FURNACE" or heater

buy a replacement..new or used..you can get one that will fit and it will cost LE$$

i don't think you can even take it far enough apart to replace just the chamber
it would be ridiculous to try and way too much labor time and expense