Let me get right to the details.... I have a 4 ton, 13 Seer, Guardian (York) Heat pump at my house. Air handler/electric furnace is matched 4 ton coil. I've been having problems with it not producing heat. Here's the situation:
I have the thermostat programmed to be at 65 degrees during the day when we are at work and it kicks up to 69 at 5pm when we get home. When it kicks up to 65 the HP comes on with the aux. heat and brings the room up to the set temp normally. Oh, and the aux kicks off when it gets to 69 and the HP continues to bring it the rest of the way till the stat kicks it off. I assume this is how the system is supposed to operate.
Now the temperature is usually in the upper twenties to low thirties this time of the night. During the evening, the stat will call for heat probably two more times before I go to bed around 11:30 or so. The first of two, usually the system will operate properly. The last time it comes on for some reason there is no heat produced and if there is, it is for a short time and then the HP quits putting out heat. When this happens, I go out to the unit and find that most of the time the compressor is running but the refrigerant line is cold to the touch and the condenser fan is running. There is no ice/frost on the exterior of the unit. This makes me assume that the unit is not in defrost mode and that it is not producing heat for some reason.
I've had a repair man (who is also a family member) look at it to determine the problem. When he looked at it, the condenser fan was not running when it should be. The fan was replaced with the proper CFM fan (875 I believe). The capacitor for the fan was also replaced. Refrigerant was low (I was told) and was added to the system. Air handler fan speed was changed to low instead of medium. After this, the unit seemed to run okay for a week or so. Then all of the sudden, the HP quit producing heat again. I go outside and find the unit running, (fan and compressor) and see sparks inside near the compressor. I immediately reached for the shut-off and turned off the unit. The sparks continued and I saw the origin of the sparks were from the capacitor that was hanging down contacting the refrigerant line and arcing. I pulled it away and called the repair man back to fix the problem he created.
He secured the capacitor back away from anything and taped over the terminals. Supposedly, this fixed the problem and the HP was producing heat. Well sure enough, that evening, the same problem reoccurred. No heat.
Repair man back out, says the compressor is kicking out from high pressure for some reason. They replace the txv valve near the outdoor unit and install a filter/dryer. Unfortunately, the same problem existed that evening.
Repair man says he has spoken with York and they say that the system should have a 5 ton coil inside to go along with the 4 ton HP outside???? We just bought this house a couple of months ago. The system is less than four years old. I have a hard time believing that the system should be mismatched to work properly, but I'm no professional. Repair man recommends replacing txv valve near evaporator coil with an adjustable txv. As of right now, that's the plan.
Anyone have any ideas if this might be the fix?
Is the system supposed to be mismatched with a 4 ton HP and a 5 ton coil?
Could there have been some damage to a circuit board or worse, the compressor when the capacitor was arcing to the refrigerant line?
What do you recommend I do?