We recently moved into a new house and this is our first winter there. Our outside unit is a RUUD model number uaka-024ja. When we turn on our heat, the outside unit runs, like a heat pump. There is also a natural gas line running into the house. How does the unit swtich from running as a heat pump to natural gas? I thought it might be automatic but the temperature was 28 degrees outside this morning and the outside unit was still running. Also, my heat seemed to have ran pretty much all night without switching off. I have a Hunter Thermostat but my only options are to switch between Heat, Cool, and Off. Any ideas?

 

After reading a little more online. Could this be what they call a Dual Fuel system? If it is, how does it know to switch from Heat Pump to Furnace? I would think if it was going to happen automatically, 28 degrees would have triggered it.

 

http://www.aepsurplus.com/upload/att...2_147_rev9.pdf

That is not a heat pump. I hope that you are not running AC and heat at the same time because of a faulty contactor outside or a thermostat problem.

 

Unfortunately it seems that is exactly what is happening. I turned the AC unit off at the circuit breaker and instantly noticed a difference in the heat. The air from the vents was a lot warmer and the unit didn't run all night long.