[bucmol]

KC13

While unit was thawing, I did some research & checking. It is a Coleman/Goodman unit model BRCQ0421BDG which I could not find listed on manufacturer's website. The closest was a BRHQ0241BB. It is a 10 SEER unit, pre Jan 06 manufacture, not the latest 13 SEER.
There are only four wires to the thermostat Red, white, yellow and green. I left the tab in between R and Rc since I only had the one red wire as stated in install directions. I reviewed the setup procedure and found that I had the "heating cycle rate" setting on 5 which is for a gas or oil furnace whereas it needed to be set to 9 for electric, which I did.
(The thermostat is Honeywell RTH5100B if that helps) Thinking that this was a central heating&air unit (only four wires) I figured that I found the problem but, while outside I noticed that the outside compressor (still) comes on. Previously, I had not actually witnessed this or I obviously would have done something by now.
I saw other model numbers that began with ER and assumed that they were heat pumps.
Now I am not sure if I should d/c the yellow wire as you suggested. An idea I had was to just set the thermostat from cent h&a to heat pump to see what would happen. I did check to see if any more freezing had occurred but none had in the 3 hour period that it was on heating fine. Should I just d/c the outside breaker for now? My AC guy is in Wisconsin until early next week or so (not sure if he is staying through Christmas or not) I am befuddled because all the things we thought it could be are covered. Do you have any other ideas, or should I still do what you (or I) thought of?
Thanks again:mad:

[KC13]

If the thermostat has a selectable option for a/c or heat pump, choose a/c. If problem persists, disconnect "Y" or outdoor power supply until your pro is available.