Suburban furnace wiring direct to thermostat

[kleinisrad]

Hello. I just replaced my Furrion AC with the Houghton model(Haven't used it in summer, but love how quiet it is). In doing so, my Furrion wall thermostat has a flashing "Error 2" code, since control box is not connected to ac anymore. Any known fix for this, or does anyone know the wiring needed to install Suburban furnace to a new wall thermostat. Thanks in advance.

Jed

[kleinisrad]

FYI, I have a 2021 Imagine 2500RL with one AC.

[Country Campers]

I am not sure of the wiring that you need to fix this. The factory wiring actually goes thru the AC and then to the furnace, weird I know. If your new AC does not have the control box I am guessing that the controls are on the AC, correct? From that I would guess that you would need to place the factory control box somewhere so that the thermostat can "talk" to the furnace.

Brian

[kleinisrad]

Hello, B/M. Yeah, I left the control box in the ceiling connected, minus the AC power connector. Error 2 code flashed. Thought there might need to be jumper somewhere in control box wiring to "trick" it thinking ac is present. I am considering installing a "smart" thermostat just for the furnace. I just need to get a diagram for a compatible thermostat.
Thanks for your input...

[ncitro]

Brian is right, the Furrion thermostat talks to the Furrion AC control box, which splits out the signal to go to furnace or AC unit as needed. If you replaced the AC, then hopefully your Houghton unit has an output for the furnace and its thermostat would run it.

[kleinisrad]

Hello ncitro. Houghton is a standalone AC. Not compatible with furnaces. It does have heat as well as AC, which will be nice on days it's not crazy cold.

[ncitro]

If you are not using the cable that runs from the AC to the thermostat, then you should be able to use that to extend the furnace thermostat wires from the AC space to the thermostat location. Then you should be able to use any residential thermostat to run the furnace. The fan functionality will not work on the thermostat, as I recall the thermostat leads into the furnace just tell it to run, and then the furnace itself determines timing and operation of the fan and burner.

howson may have the wiring diagram for the furnace.

[kleinisrad]

Ncitro, thanks for the input. Using the wiring from AC should make it easier.

[howson]

If you are not using the cable that runs from the AC to the thermostat, then you should be able to use that to extend the furnace thermostat wires from the AC space to the thermostat location. Then you should be able to use any residential thermostat to run the furnace. The fan functionality will not work on the thermostat, as I recall the thermostat leads into the furnace just tell it to run, and then the furnace itself determines timing and operation of the fan and burner.

howson may have the wiring diagram for the furnace.

Neil--I'm a bit tired so maybe not completely understanding this thread, but my first thought is it's not an easy task installing a residential thermostat in an RV. Usually residential thermostat's run off of 24vAC(?), something not readily available in our units.

So I don't have to repeat your research, where did you and Brian ( Country Campers ) find that the furnace signal runs through the a/c control box?

[kleinisrad]

Hello howson. I am considering the Micro Air Easy Touch thermostat to wire directly to furnace.

[Country Campers]

Neil--I'm a bit tired so maybe not completely understanding this thread, but my first thought is it's not an easy task installing a residential thermostat in an RV. Usually residential thermostat's run off of 24vAC(?), something not readily available in our units.

So I don't have to repeat your research, where did you and Brian ( Country Campers ) find that the furnace signal runs through the a/c control box?

I am going off of memory. I thought we learned that the single thermostat, operates the ac and the furnace, went thru the ac before the furnace, or the thermostat had to have the connection at the ac to operate the furnace.

Brian

[howson]

I am going off of memory. I thought we learned that the single thermostat, operates the ac and the furnace, went thru the ac before the furnace, or the thermostat had to have the connection at the ac to operate the furnace.

Brian

It depends on the OEM, Brian. I know both Dometic and Coleman-Mach wire it differently. I'm not 100% sure on the Furrion. Hopefully I'm remember to look in the morning for some schematics...

[ncitro]

The micro air is designed to go through the AC control board, so I don't think you want to go that route since your AC won't run the furnace.

Howard, in my old SOB RV I used a residential thermostat that was battery powered, so it didn't need the normal 24v c wire. This became more difficult with the digital thermostats they switched to where the logic was in the AC unit rather than the thermostat itself, but I figured if he was looking to only run the furnace it shouldn't be an issue. I'm just not sure on the suburban where the wires map out for the thermostat. I thought you had figured this out at one point for some reason.

[ncitro]

howson This was a while ago, but may be the discussion I was thinking of.

https://gdrvowners.com/forum/operati...iring-question

Colan states shorting the two furnace wires will tell it to run, so when looking for a thermostat you want something that is either 12v (and can run off the rig power, this is a rare find) or a battery powered one. Then find your furnace wire in the AC space (may be white but test to be sure, RV colors are not always followed) and connect that to the furnace terminal of the thermostat. Power it with either a battery or rig power (or I suppose a 12v to 24v converter) and you can eliminate the Furrion board.

[kleinisrad]

Thanks for all the info!