Had an electronic thermostat go bad, so I replaced with same exact kind. We have 2 seperate systems, both with the same exact type of thermostat, so I just assumed the electronics went bad in the 1. Both (thermostats) have worked for 1 1/2 years with no problem. After replacing, the outside unit runs all the time, even when the temperature indoors is where it should be (satisified). I should mention that both units are Goodman heat pumps. We've had nothing but problems with BOTH units, and have had both compressors replaced, among other things. We bought the house brand new 5 years ago. I'm so irritated, (and financially strapped), I need to try and fix this myself. The contractor who installed ours also installed several dozen others in our sub-division. Most of my neighbors have had no problems with theirs.

 

If you pull Y wire off the tstat . Does it stop????? or run then