Spring of 2026 Only Emergency Heat works.
Donnelly guy came out said it could be freon issue but needs it to get a temperature differential to test freon amount.
He would call when available. He never called.
Still over summer cooling AC worked fine.
Now in October normal Head is not working.
I feel cool air coming out of vents.
Fan never spins outside.
Gemini AI
Based on the symptoms of your York YHE30B21SB heat pump, the issue is highly likely a failed defrost control board, a stuck reversing valve, or a bad high-pressure switch rather than a Freon charge issue. [1, 2, 3]
Because your air conditioning worked perfectly all summer, we know that the compressor, the dual-run capacitor, and the outdoor fan motor itself are mechanically and electrically sound. If the fan or capacitor were dead, the AC would have overheated and failed over the summer. [1, 2, 3, 4, 5]
The root cause of why normal heat fails while the outdoor fan remains stationary includes the following breakdown:
1. Defective Defrost Control Board or Fan Relay
The outdoor fan on a heat pump is routed directly through a relay on the defrost control board. [1]
The Symptom: When you switch to "Heat" mode, the board fails to send the necessary 24V signal to flip the relay and power the fan.
The Result: The indoor blower runs and pushes unheated air (cool air) through your vents, while the silent, motionless outdoor unit forces your thermostat to fallback exclusively on Emergency (Auxiliary) Heat to keep you warm. [1, 2, 3, 4]
2. Malfunctioning High-Pressure Vapor Switch
York units utilize a high-pressure safety switch wired in series with the outdoor fan. [1]
If this switch is faulty or has failed open (a common issue on these York mid-tier 14 SEER platforms), it cuts power to the outdoor fan immediately to protect the system, completely preventing it from spinning in heat mode. [1, 2]
3. Stuck Reversing Valve
The reversing valve is what physically alters the flow of R-410A refrigerant to switch your system from cooling to heating. [1, 2]
If the valve is mechanically stuck in the "cooling" orientation, the system cannot harvest heat from the outside. When you call for heat, it operates backward, sending cold air inside. [1, 2, 3]
Next Steps & Contractor Advice
The Freon Myth: The previous technician's claim that he "needed a temperature differential to test Freon" in the spring is partially true for basic pressure charging, but York's official guidelines state that the definitive way to check a heat pump's charge in heating mode is to weigh the charge in rather than relying solely on ambient pressure splits. [1]
Action: Do not run the normal "Heat" mode if the outdoor compressor hums but the fan stays dead, as this can overheat and permanently damage your compressor. Keep the thermostat set to Emergency Heat until a different, reliable technician can test the voltage outputs on your outdoor defrost board and check the pressure switches. [1, 2, 3, 4, 5, 6]