I had a GeoComfort GXT Series unit installed about 3 years ago to heat & cool my home. I didn't have any issues with it until recently when it failed to cool my home. I was told all I needed to do was to maintain the filters & keep them clean, which I've done. It has good air flow through the vents & good suction in what I think is the cool air vent. The fan is constantly running to reach the desired temp, which I only change within a 2 degree difference when adjusting. There is also a random, almost electric, shocking noise, I hear through the vent. the unit sets almost directly underneath it in my basement. Also, beside the "On" switch on the unit, the light is Orange & I remember it always being Green. The air coming from the vents isn't as warm as the heat would be or as cool as the air should be. I shut the entire unit down, hoping it would "reset" itself but nothing changed. There's no water, freezing or visible condensation on or near the unit. I'm not sure what I can or should check. I did contact the installer which agreed to come out for $150 for the first hour. I really can't afford that & would appreciate any insight that may help. Someone did mention it could be the TXV & it may be stuck. is that possible & if so, something I can check myself?