Carrier error code P1
What it means
Low voltage protection.
Possible causes
Line voltage below operating threshold Volt drop across long or undersized cable runs Unstable utility supply
Suggested fix
Check voltage at the unit during starting and running and upgrade wiring or address supply problems to bring voltage within specification; only clear the protection once a stable supply has been established.
Safety first. Isolate the power supply before inspecting any unit. Refrigerant-circuit
and electrical repairs must be carried out by a qualified, registered technician.
Other Carrier codes
- E1 — High pressure protection in the refrigeration circuit.
- E2 — Evaporator coil temperature sensor fault.
- E3 — Low pressure protection.
- E4 — Compressor discharge temperature protection.
- E5 — Overcurrent or overload protection.
- E6 — Communication error between indoor and outdoor units.
- EC — Refrigerant leak detection alarm.
- F0 — Low refrigerant protection.
- P0 — High voltage protection.
- P4 — Fan speed fault.