Compatible Residential Thermostats ????

Raymon wrote:

Dutch_12078 wrote:

msturtz wrote:
While a residential thermostat may "work" they are designed for 24V AC not 12V DC. According to Coleman tech support the use of a residential thermostat can damage the control circuits over time which would require replacement. The thermostats are no longer simple switches. They strongly discourage the practice of replacing the thermostat with a residential unit. All RV HVAC equipment control circuits are 12V DC.

The Honeywell RTH2300 digital thermostats I installed work just fine using the two AAA batteries inside the case. I replace them annually. The specifications include "Works with low volt heating/cooling systems including millivolt..."

The two AAA batteries only power the thermostat. The 12VDC control voltage comes from the AC unit itself through the use of a step-down transformer. I myself would only use a thermostat rated for 12VDC. Replacements are available; I have ordered them over the internet.

Ray

The Honeywell RTH2300 uses relays to do the switching done by the bi-metal coil contacts in the analog stats. Mechanical switches handle the heat/cool and fan functions, just as they do in the analog stats. The relays and switches are rated to handle 24-volt residential systems as well as millivolt systems, so the RV 12-volt systems present no problems. The furnace's and AC's don't care what is operating the contacts, just that they open and close. I installed the non-programmable version of these same stats in our previous coach in 2008, and they're still working perfectly. A search on this forum will find numerous threads about similar successful digital installations using Honeywell, Hunter, and other digital residential stats.