HVACopediaCarrier · Heat pump troubleshooting
Outdoor unit unresponsive after several faults
What is going on
After some combinations of earlier fault codes the outdoor unit can stop responding even though nothing is broken.
Likely causes
- Control latched after earlier faults
Check in this order
- Turn off high voltage to the outdoor unit for at least 2 minutes, then restore power.
- Remember the 10-minute sump warm-up delay after power-up (code 68) before full operation.
- If the unit still does not respond, troubleshoot with the STATUS light codes.
Applies to: Carrier Infinity 18VS variable speed heat pump 25VNA8
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Source: Carrier 25VNA8 / 24VNA9 Service Manual, Status Codes note p.14. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.