My Heat pump which is a Trane and 20 year old iced up a few weeks ago. The HVAC technician said nothing was wrong , that when the temperature is below freezing I need to turn on the emergency heat.

I did that a received a $430 electric bill this month.


I have not had this problem for 19 years. It froze up again last week so i turned on the emergency heat again.


What could be causing this. Do I need a new thermostat?

If the unit is freezing up or getting ice on it the defrost circuit is having a problem. Defrost timer,defrost circuit board,defrost sensor,reversing valve or the reversing valve activation coil is defective causing the problem. Call a better service company and tell the to find the defective part and fix it.

Now I will say 19 years is a long time on a heat pump and you might consider a replacement due to age and the possibilitys of other problems happening.

I do not believe a new thermostat will cure your problem. The qualified service person who looks at your system will be much better informed than I can be since I am not there to test your syatem.

You could be having a problem with the defrost control malfunctioning, this control is located in the outside unit and defrosts the unit on a time and need basis, Good luck, Mike

Get a new tech and have them find the problem in possibly your defrost subsystem. That system is there specifically when the temp goes below freezing to prevent exactly this situation.