Thermostat question

[Iraqvet05]

I installed a Honeywell RTH111B1016 digital thermostat in place of the old mechanical Coleman Mach. Let me first off say this is not an easy install of you plan to do add a fan switch for a dual speed fan. I purchased the Honeywell based on an article in a Trailer Life but the case on this thermostat is just too small to accommodate a toggle switch but with some Dremel hacking I made it work.

Anyway, I could not test the A/C at the storage unit (no 120V power source) and the ambient temp was too high to trigger the heat. I had assumed the "fan only" setting on the thermostat was 12V but it it actually 120V?

[Camping Couple]

With your thermostat removed from the sub base, you can jump R to Y1 to test AC. R To W1 to test heat. If everything works, you can put the thermostat back on and your good to go.

[Grumpy]

Originally Posted by Iraqvet05

I had assumed the "fan only" setting on the thermostat was 12V but it it actually 120V?

Yep. The a/c fan is 120 and all the fan swtich on the thermo does is close the relay for either HI or LO fan.

[Firefighter78]

I just did the analog to digital conversion on my Coleman A/C unit. This was a nightmare, found out that the digital thermostats you buy at the local home centers for household use are 24VDC. RV thermostats work on 12VDC. After calling Coleman, I had to give them the model, serial numbers off the AC unit which are found by removing the ceiling cover. They gave me the correct part number thermostat to buy which was like $70 from them. It works perfectly. Good luck

[Iraqvet05]

We went camping this past weekend and everything worked correctly...well, at least on the a/c side. I took a few pictures and notes of the stock wiring just in case I had to revert back to the old thermostat but luckily I didn't have to in the 90 plus degree weather. I really enjoy the temperature consistency with the new thermostat.