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lakeviewpastor · Jul 7, 2009, 01:52 PM

My AC went out of my Mobile Home, It was a unit incorporated with the heat system. The heat still works fine. I bought a cooling unit that is an all in one unit and tapped into the supply line for the vents and ran a return but I am having problems with the thermostat wiring. How do I need to wire the Thermostat differently to run the AC unit or do I have to install another thermostat?:confused:

wmproop · Jul 8, 2009, 08:27 AM

Need to know what kind of tstat you have,for starters, brand and model number
Is it heating/cooling or heat only?
How many tstat wires do you have?
What kind of (brand) a/c unit do you have?
Do you have gas/electric/oil furnace?

lakeviewpastor · Jul 8, 2009, 10:26 AM

Thermostat is Hunter 44100B, It it a Heating and Cooling. It has 4 wires Green, Yellow, Red, and White, There is also a blue that is not connected. The AC unit is a Coleman and the Furnace is Electric. Thanks for help

KISS · Jul 8, 2009, 01:33 PM

This sounds like your using the old heating system and the new cooling system and would like to use a single thermostat.

With two systems, that usually means two transformers and the use of a stat which has Rc and Rh separated rather than jumpered.

Also, some moble homes, specifically Coleman may have had a switch at the furnace to switch from AC and Heat. Does yours?

All of this complicates things, if true.

lakeviewpastor · Jul 8, 2009, 02:47 PM

The original system had both heating and cooling. I am still using the heat but the compressor went out on the cooler. I could not afford to replace the whole cooling system which was what a pro told me needed to happen. I purchased a used self contained cooler. All I need to do is hook up the thermostat so that I can switch to cooling and turn on the new cooling unit. Right now the thermostat is jumped from RC to RH. I don't know of any switch at the furnace to switch between heat and cool.

KISS · Jul 8, 2009, 04:20 PM

If your cooling system has a 24 VAC contactor that needs to be supplied power to turn it on, then all you have to do, is connect the Y (call for cool) lead of tsat to one end of the contactor.

The other end might be problematic to find. It's the other side of the secondary that does not go to W (call for heat). Again, assuming the 24 VAC turns on the heating system.

G (fan) may be required too. Not sure if your using the same fan as the heating system for AC.

mygirlsdad77 · Jul 8, 2009, 04:21 PM

Honestly, your best bet here is to install a separate thermostat for the cooling unit. Keep it completely separate from the funace and you will have no problems. When you get the new stat, make sure it is a cool only stat. This will simplify the wiring.

One note, most people get rid of the separate cooling system in exchange for a central air system(which you had). I would have replaced the condenser before installing a separate cooling system. I would keep my eyes open for a used condenser to get your setup back the way it should be.

lakeviewpastor · Jul 10, 2009, 05:54 AM

I got the unit going. I put it on its own thermostat, the problem now is it won't quit. It doesn't shut off, woke up this morning to a freezing cold house. It even runs when the thermostat is turned off.

wmproop · Jul 10, 2009, 09:47 AM

Either you have a wire on the wrong spot, or possibly you have a stuck contactor,
But if both the indoor airhandler and the outside unit doesn`t cut off its probably a wiring prob.