I'm not sure of the heat and air unit we have but our thermostat is White-Rodgers. Our repair guy has been out over 1/2 a doz. Times but our problem still remains. When he comes in "fixes" the problem and not to long after he leaves we find that it wasn't fixed at all. When set on regular heat, we have to set it at 72degrees or it simply blows cool-cold air, when it hist target temp. it doesn't kick off on Auto. The only heat that is working is emergency heat. I'm sure he's telling us a bunch of bull. He says it is suppose to do that, that the fan will not kick off unless the thermostat is turned off and if is set at any other temp. at all it doesn't work. First he said it was losing it's signal because it was so dirty so they cleaned it. Then it was a wire not hooked up. Then he blew the circuit board, then the transformer, the last part was installed today and we are back to the same problem. Please someone respond, we already went without heat for over 3 days and had to go out and buy space heaters and it is very cold here- in the teens and 20's and have children... Can't afford a huge electric bill especially now at Christmas.

Sounds like you have a heat pump. Average temp out of the supply grill will be around body temp-- 98 degrees. But it should keep up with in 2 degrees of what you have the t-stat set at. Say if you got it set at 72 the temp in the house should not be 65. A heat pump is made to keep a more constant temp, when it gets colder outside say below 30 it works a little harder and runs more.

You need to change repair guys. Your low voltage wiring needs to be checked for proper install. The stat needs tp be checked to be sure it's worried properly. The heat pump needs to be checked to make sure it is wired properly. This definitely sounds like a wiring deal... Needs ot be all pulled apart, ohmed out and rewired. That's a good place to start.