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.

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

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..."

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.

I put the same Honeywell learning thermostat that we have at home, into our 5er. It will learn how long it takes to heat or cool to the set temp, so it is at the temp you set at the time you set. I don't do low speed AC. If I have the AC on, I want it on high. It would be easy to add a switch to be able to select it if you would prefer that.

At home we have a 95% efficient furnace, and I wanted a "smart" thermostat to make use of it. It isn't "smart" by todays standards, but I only have to learn one thermostat this way.

I converted the two analog stats in our coach to Honeywell digital programmables. I added a small toggle switch to handle the hi/lo fan speed selection. The wiring conversion was pretty straight forward.

There are any number of residential ones that will work. On our previous coach I used White Rodgers units and wire the high speed fan to the 2nd stage compressor terminal and used the internal battery as a power source.

On this coach I'm looking at a Honeywell Pro 5000 but the basement air with 2 compressors and two fans present unique challenges.

our roof top air is not a heat pump - it has a heat STRIP.

A thermostat is basically an on-off switch, that is controlled by temperature. They have inexpensive analog type dial thermostats(No digital readout) that may work just fine to turn ONLY your AC on and off.
With the heat pump, then you will need a thermostat that can handle both the heat and cooling functions and switch the proper valves to reverse the operation.
The only thing you need to do is look at the wiring diagram and figure out which wires turn the AC on and off and hook them up to your new thermostat. Taping off the other wires to be used at a later date when you install the full function thermostat.