I have a York heatpump, outdoor package unit last week the weather cooled down and we switched the t-stat off, last night I noticed the emergency heat light was on, I switched the t-stat to cool and the air handler comes on but not the compressor, and the emergency heat light remained on. I cycled power on the unit and after about 1 or 2 minutes the emergency heat light came back on. What's up can anyone help me??