Furnace thermostat

Pepper2 · 04-27-2012, 04:59 PM

What have you used as a replacement to the Coleman thermostat? I want one that cycles more often, keeping the temp. more constant. Would like to stay away from adding a toggle switch for high/low fan. Thanks!

puterbug · 04-27-2012, 10:55 PM

I don't think you will find one that cycles more often. There used to be a Honeywell "hack" for the Coleman-Mach, but Wally world doesn't carry it anymore and it didn't always work. I installed one on somebody else's and it worked great. On mine, not so much. I ended up getting a new Coleman Mach t-stat.

Pepper2 · 04-28-2012, 02:46 PM

Ended up using a Hunter digital heat/cool t-stat. Taped off the gray and blue wire, so we'll only have high fan in a/c mode. Ran the heat (45* here) for about an hour and the temp only varied 1 degree and it only cycled 1 time in 25 minutes. Happy camper here!

Musicman · 04-28-2012, 04:22 PM

I am going to do this mod this week. If you don't mind me asking, which Hunter did you buy?

George Schweikle · 04-28-2012, 07:56 PM

Somewhere on this forum there are instructions for installing a Hunter thermostat, and adding a little toggle switch from Radio Shack that allows running the fan on both high and low speeds. I did this last fall, and it works fine. I'm sure you can find this thread with "search"

Quote:

Originally Posted by Pepper2

Ended up using a Hunter digital heat/cool t-stat. Taped off the gray and blue wire, so we'll only have high fan in a/c mode. Ran the heat (45* here) for about an hour and the temp only varied 1 degree and it only cycled 1 time in 25 minutes. Happy camper here!

Pepper2 · 04-29-2012, 05:17 AM

It is the model #42995. Since you need the battery type I got this model due to the side door for changing the batteries. Much easier then the others I looked at. And yes you can add a toggle switch to utilize both fan speeds. I have never used the low speed so I skipped the switch.

garym114 · 04-29-2012, 08:10 AM

Hunter Thermostat
Information for DuoTherm and Coleman thermostat replacement.

The Hunter thermostat used is quite old now and is probably not available so don't get hung up on that. Any thermostat that operates on battery power, usually AA batteries will work and Hunter makes several. The red wire coming out of the wall is not used. It is 12 or 7 volts DC from the RV battery. Tape it over so it won't short out on anything.
I never understood his approach to wiring in the fan switch. Out of the wall the blue and tan wires are Hi and Low fan speeds. In using a single pole double throw switch a wire should go from the center connector on the switch to the fan wire connection on the thermostat and the blue and tan wires to the top and bottom connectors on the switch.
A miniature switch is easier to mount. Just drill a hole big enough for the threaded portion to go through and tighten it down.

Pepper2 · 04-30-2012, 03:38 PM

Bought the t-stat yesterday, and you could be right about it's age because it was the only one left at Wally World. But as far as wiring mine, the red was used. It hooked to red heat with a jumper to red cool. I taped off the gray and blue. Seems to be working O.K.. Am I missing something here?

taboky · 05-02-2012, 06:48 AM

I did my rig last week. Yes, I had to use the red power wire. When I had my 5th wheel and did this mod, it didn't use the wire. I camped this past weekend and it was cold. Was real nice waking up in warm RV. Also, instead of using the toggle switch for fan speed, I mounted a switch to the wall beside thermostat. Sorry for fuzzy pic, camera phone.