Furnace / Duo-Therm thermostat question

[RoamingPD]

Hello, we recently purchased a used 2007 Cardinal 30LE. We just sold our home in RI, and will be traveling extensively across the great USA this fall, eventually ending up in Colorado. Of course, the unit did not come with any manuals, and last night we tried to use the furnace for the first time, as it's a little chilly in Weedsport, NY.

When I switched the Dometic Duo-Therm thermostat from "cool" to "furnace" (fan switch set to auto), then raised the temp. slider, the a/c ceiling vents started immediately blowing cool air. This seemed strange, but I thought maybe the a/c also had a heat pump. I then checked the model # of the A/C (59516.336 Quick Cool) and it does not appear to be a heat pump unit. Anyway, I left the unit on for several minutes, but the furnace never fired or made any kind of noise like it was trying to light, and nothing ever came out of the floor vents. What am I missing here? Any help would be appreciated, I'm an RV newby.

[08flagvlite]

You are correct that those floor vents are strictly for the heat. It is a totally separate system than the rooftop AC setup. You should be able to run the heater blower on "fan" or "heat" option. They are both controlled by the same thermostat. You may have an inline fuse blown, found near the heater unit- usually behind a removable panel possibly a cabinet rear or side wall, depending on the design. Those thermostats are also very low quality- most people replace them with a single stage heat pump digital thermostat, as I did. There is only like 6 wires, and it is a pretty easy install. Randy

[RoamingPD]

The solution was to replace the thermostat. I had the RV in for service, and the service center tested the furnace and found that the Dometic thermostat was malfunctioning. Furnace is working fine now, although, we are down in Florida, and haven't needed it for awhile.

[NorminN.B.]

I just bought a honeywell digital thermostat to put in my 39L Cherokee. It was windy out when I started to change it. When I took off the old one, there was so much breeze coming through the fist size hole, where the wires came out. I changed my mind until I can stuff some insulation in that wall. It is an inside wall, so I don't know where the draft is coming from. I was afraid the digital thermostat would never shut off. NorminN.B.