Need help!
I have Intertherm furnace and a\c system model number MGH-100-ABWN-05 while the heat\a\c switch on the furnace is on A\C my thermostat can't control it. I have a electronic thermostat made by ritetemp (model number 8030C). I do have the RC terminal jumpered to the RH (r on the furnace) like the manual said to do. I tried it on the heat mode and a\c Mode, I have also tried turning up the temperature higher that what's the current temperature in the house is and it still stay on... But in the heat mode the heater works great beside every once in a while last winter the furnace shutdown due to the Blower motor heating up. Have any Ideas on that one?

Thanks for the help.

Michael

Either the wrong thermostat for that set up, or you have 2 transformers and Rc Rh should not be jumpered. Did you have an extra wire?

No just two wires coming from the furnace terminal R and W.

There are only two wires sticking out of the wall that you hooked up to the thermostat?

Mobile home thermostat is needed. Or you have to run a new thermostat wire and redo all the controls in the A/C conversion box in the furnace.

Yes, only two wires sticking out of the wall that comes from the terminal board on the furnace. This house was built back in 1988.

Northernheat is correct. When you have a cool off heat switch on the furnace you only can use a 2 wire thermostst. The controlling relay part is in the furnace box. I have never found a electronic thermostat that will work with that setup.

Thanks guys. I'll try a dial type thermostat and see if that fixes the problem. If not, I'll get a tech to come in and look at it.

Talked to a rep from Ritetemp and got the problem solved. I had to remove the jumper wire from the rh to the rc terminal and switch the thermostat to heat mode and switch the switch on the furnace to the a\c position. Then this winter switch the it back to heat mode and reset the temperature to proper level.


Michael