Error code reference

Samsung Heat Pump Error Code P4

Reverse phase or missing phase error detected on 3-phase power supply to the outdoor unit.

First step from the service manual

Check L1(R)-L2(S), L1(R)-L3(T), L2(S)-L3(T) phase voltages and verify 3-phase power with a 3-phase tester.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

$29/month · Cancel anytime · Or $9.95 3-day pass

M+

M+ Max·Samsung Heat Pump

P4 on my Samsung Heat Pump

M+

Reverse phase or missing phase error detected

From Service Manual 392054, p.26:

1.Check L1(R)-L2(S), L1(R)-L3(T), L2(S)-L3(T) phase voltages and verify 3-phase power with a 3-phase tester.

2.Measure door lock assembly resistance across the PTC terminals. Expected: ~200 ohms cold, rising sharply once energized.

3.Inspect strike and latch alignment. A warped door or misaligned strike prevents the switch stack from closing in the correct sequence.

Part DC34-00024B

Door lock assembly

78,000+ service manuals · 160,000+ error codes · 55+ brands

$29/month · Cancel anytime · Or $9.95 3-day pass