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Hello it sounds like the contactor welded itself shut. So to check this go to the out door unit turn off power and remove the control cover look for the contactor it will have a plunger in the middle. Push down and release it should move freely. If it is stuck you can break it free but you will need a new one. They run about 20 to 30 dollars. Once you check this let me know if that is or is not the issue and we can continue. Thank you Richard
OK. I dropped power. Disconnected wire connected to Y terminal on the thermostat. Restored power. Unit still kicked on despite thermostat in "Off" position. Dropped power again. I'm in the process of trying to find the right Y terminal on the indoor unit to pull a wire from. Sorry it's taking me so long. This isn't exactly my field of expertise!
Hello Ok we are missing something in translation. You disconnect the Y which is the compressor wire from the termostat. Yet you say it responds to the thermostat but compressor is running all the time? It's one or the other either the unit turn on and off with the thermostat or it runs all the time.
Next when you say compressor do you mean the out door unit? condensor? or the compressor motor inside the condensing unit? Richard
Sorry I wasn't clearer.
I disconnected the wire from the Y terminal on the thermostat on the wall. There was no change in behavior. The heat pump and condenser both kicked on, regardless of thermostat settings.
I disconnected the wiring from the Y terminal on the circuit board within the heat pump inside. With this action, the heat pump now responds to thermostat settings. Also, the outside unit (condenser, not compressor -- sorry) runs regardless of thermostat settings.
Please let me know if you need more clarification or information.
Got it. Forgive my ignorance and use of the wrong terminology.
You are correct. With the Y wire off the air handler the condensor is running yet the contactor moves freely.
I checked out the wiring running to the condensor outside. The wiring (including the wire that runs to a Y1 terminal) is wrapped in a sheathing that has a point where there was some wear to it (it had been rubbing against an edge of sheet metal on the unit). However, that part of the wiring bundle/sheathing had some electric tape wrapped around it.
Last December, I had to have a service call because the system wouldn't run at all. The technician found that the sheathing containing the wiring bundle had been rubbing against the sheet metal edge; exposing some of the wiring. He wrapped it in eletric tape and that seemed to fix things. Hmm... even though this wiring bundle was wrapped in electric tape, I'm wondering if this is the root cause? Thoughts?
Richard, I think we've got it. I stripped back enough of the sheathing on the wiring bundle to expose the wiring where the insulation around the individual wires had been worn away. I wrapped each of the wires that had insulation worn away in electrical tape (including the yellow wire). I reconnected all disconnected wiring and restored power to the air handler and the condensor. The system now responds to settings from the thermostat (heat/cool, on/off). While using the electrical tape in place of properly insulated wiring isn't a long term fix, I at least know where to root of the problem is. Thank you very much.