P1
Haier Low Voltage Protection / Power Supply Under-Voltage

Indoor unit displays P1 and the unit may not start or may shut down unexpectedly.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Supply voltage below Haier specification, Loose neutral or live connections, Undersized wiring causing voltage drop, Faulty power supply board

How to Fix / Troubleshooting

Safety first: Turn off power before tightening any electrical connections.

  • Measure voltage: Have a qualified electrician measure voltage at the unit during operation. It should be within the range specified on the nameplate.
  • Check connections: Tighten all terminal screws at the indoor and outdoor units and at the breaker panel.
  • Reduce load: Avoid running other heavy appliances on the same circuit.
  • If voltage is normal: The internal power supply or sensing circuit may be faulty and the PCB may need replacement.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Power Supply Circuit (Indoor or Outdoor PCB)
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements