Replace Dometic with Honeywell Thermostat

[RobKat]

After putting up with 5 degree temperature swings I decided to figure out why I was constantly going from hot to cold and back again. As the temps outside I wanted them more constant inside. It all came down to the thermostat. The Dometic analog (with temp slide) was definitely the problem. Spending was a consideration - I wanted a good thermostat but with features.

I finally settled on the Honeywell 5.2 Programmable. Perfect for what I wanted.

I researched a few forums and also the manufacturers recommendations. My system is a Suburban LP furnace and Dometic roof mounted AC. I used the color coding of Red (cap it off), Yellow to Y (cool), Brown/Blue both to G (fan - high speed), White to W (furnace), Green to RC/RH.

In my case I also an Orange Lead (I capped it off - it is to the warmer in the AC unit - an added feature).

It took 30 minutes. Time well spent. The unit runs a little more but the temp swing is gone. I have a 1 (at most 2) temp change before the unit comes one.

Best of all - it is programmable. I now wake up to a warm (or cool) unit. No more fiddling with the old slide and end up hot and cold.

The big NOTE that anyone who wants to make the same change - the thermostat must be able to work with 12V systems.

[10x]

What model did you get?
Where did you buy it?

[RobKat]

I purchased Honeywell Model #: RTH6350D1000 at Lowes

Honeywell 5-2 Day Programmable Thermostat.

If you are really into tech you can buy the one with WiFi.

[traveler2955]

Added note to some who may have issues with temp, but not necessarily the thermostat.

Our limit switch, relatively new I might add, failed and was replaced shortly thereafter. The new switch had great variance in temp which randomly made the cabin hot and cold. A subsequent new switch solved the problem.

My guess, limit switches are not quality controlled as tightly as one might think. A second switch which was tested by me now resides in our spares locker, and because I have a second switch I'll never have this problem again.

Just a thought.

Mike

[RobKat]

Update - We've been enjoying the comfort of a warm MH. No problems have been encountered. It is nice to wake up to a warm coach. I also do not have to remember to turn it down at night. I do wish I had bought the broadband ready. That way I don't even have to be home to change the temperature. Totally spoiled.