Suburan Model SF-35 Furnace issues 2001 Adventurer

[Kyle]

Hello! I am a year long into RV-living. It's had its own ups and downs.

I am in a pretty good condition 2001 Adventurer (32ft workhorse).

I am living with my Fiancé.

Anyways, I received a phone call from her last night while I was out at work, She claimed the RV smelt strong of cigarette smoke while turning on the heater. She turned it off instantly and I came home to take a quick look.
*We don't smoke*

I changed out the air filter in hopes that it would help *I have 2 hairy cats and I change filter out every other week due to their hair*. No luck. The heater blower would kick on for approx 30 seconds, then kick off.

Today, I went to try and see what happens.
I turned the ELEC heat on *I normally use this setting all winter long, I am hooked up to 50 amp outlet, heater would work normally, vents from floor produced heat, and the ceiling vents produced heat* Went outside to the rear and looked at the furnace. It kicked on, the sail switch compressed, blew cold air out the vent, turned off and then the AC unit turned on.

I then went back inside, turned on the furnace using GAS HEAT setting on my thermostat. It kicked on, went outside, sail switch compressed, flame ignited. Went back inside. Now the heater is working on gas heat. floor vents are producing heat.

I decided to switch it back to ELEC HEAT to avoid using propane. The blower kicked back on and is producing heat through floor vents. about 2 minutes later, the floor vents are still producing heat, but then the CEILING vents started to blow COLD air.

Any ideas? I mean, I'm glad its heating up again on ELEC HEAT. Should I just close the ceiling vents and let the floor vents do it's thing?

Any ideas on what to do?

I CANNOT REPLICATE OR SMELL CIGARETTE SMOKE

[wahoonc]

I am not exactly sure of your unit's configuration. However, the rooftop units are heat pumps, if the temperature outside drops below 40 degrees (roughly) the gas furnaces will come on to compensate, and the rooftop fans will continue to blow to help distribute air. Or you can switch over to a gas heat only. We get the occasional odd smell when the gas first kicks on for the season due to dust build-up in the heat exchangers. It usually goes away quickly.

If the outside temperature is above 40 and the gas units are still kicking in you probably have either a bad connection or the controller is going bad.

Aaron

[jefflbi]

I just resolved an issue with my SF-42. According to the manual, even with the thermostat set to electric heat, if the difference in temp is more than 5 degrees, the system will tell the gas heater to help get the temp within that 5 degree range. The gas heat comes out the floor vents and the electric heat comes out the ceiling vents. As a safety precaution the gas heater will run the blower for a few minutes after it shuts down to make sure there is no lingering propane. My issue was the heater blower was running 24/7 and I had to replace the control board to resolve the issue.

[Ray,IN]

I'm assuming you have a basement heat pump/air conditioner and said furnace.
This service manual, has a great troubleshooting section, plus a chapter on the thermostat and how it works and when..
https://bryantrv.com/docs2/docs/rvp/6535heatpump.pdf

[Kyle]

Hello, sorry for the late responses. I am still having an issue, I believe my thermostat or ac is giving up completely. It's not cooling anymore.

here's what happens:

I will turn the AC on, I will then check the voltage to my yellow and orange wiring (compressor 1 & 2). my orange wire will have about 11 volts and the yellow wire will have none. Then I hear a click. I recheck my orange wire, 0 volts... I don't get it... Is it because it's cold enough outside it can just read that it'll do fine with just recirculation?

[Ray,IN]

"Old-Biscuit" on irv2.com is the forum appliance expert, locate one of his posts/replies and ask him to help.

[mikf]

Did you get it figured out yet? If not, you need to know that the electric heat only comes out of the ceiling vents. Same vents as the AC in summer time. Gas heat ONLY comes out of the floor vents. When the outside temp drops to a certain point the heat pump will turn off and gas will come on automatically if you have thermostat set to electric. If you have the thermostat set to gas only the propane furnace will run. Which if it is very cold outside you should leave it on gas because only the gas furnace will heat the basement and keep your pipes from freezing. Electric heat will not heat the basement.