I've had a company come out and tell me the ac and furnace are ran from 2 different fans and they recharged the AC unit. However, prior to this the AC was still freezing over the lines. If I have the thermostat set to 80 for the AC it still blows out air so cold and it freezes over the lines and will not shut off until I unplug it from the main outlet. The inside temperature reads to the lowest of 60 degrees even if I have to set to 80 degrees it just will keep running. When I turn the air off from.the thermostat the ac unit itself will still be running outside but not blowing air inside. The furnace is only 4 years old the AC unit however is 23 years old. Not sure about the thermostats age.
Why is the AC only blowing out Ice cold air and freezing over AC lines
hvac
Related Topic
- Blower motor runs won’t shut off no heat
- Does a central A/C with copper lines that are too small cause compressor and diaphragm failure
- Two ducts Blowing hot air, 4 ducts blowing cold air
- Gas Furnace blowing hot air into room, flue is cold
- Inducer Fan Blowing Out Flames and Pilot Light on Carrier Furnace
Best Answer
If the outdoor unit continues running while the indoor blower is stopped it would indeed start looking like a freezer. If there's been work done recently on the thermostat and related wiring then it could be that a mistake was made which causes the compressor to run continuously. If this problem has developed spontaneously, a likely cause could be that the contactor in the outdoor compressor unit has welded itself closed. That's the equivalent of the power switch being stuck in the on position.
An HVAC contractor or other person comfortable with a volt meter should be able to identify pretty quickly whether the call for cooling is stuck on, or whether it's the contactor itself that has failed. There should be a pair of small-gauge wires going into the compressor unit. If there's a voltage showing between those two wires (about 24 volts ac), or if disconnecting one of them causes the compressor to stop running, then the call for cooling is stuck on -- a thermostat failure or a wiring problem would be likely. If instead there's no significant voltage between the two wires then the contactor is stuck and should be replaced.