Error code reference

Samsung Heat Pump Error Code E428

Outdoor unit compression rate 1 error (compression ratio over 8.5 for more than 5 minutes).

SourceSamsung Heat Pump - Service Manual: Troubleshooting & Error Codes (AVMWH020CA0G)p. 221, 258

Diagnostic procedure

The full E428 procedure

Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.

MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
Check service valves; check PWM valve coil and connector; check refrigerant.

SourceSamsung Heat Pump - Service Manual: Troubleshooting & Error Codes (AVMWH020CA0G)p. 221, 258

More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
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Where this code is documented

5 manuals in the MyPros+ library document this code for Samsung heat pump.

Models covered by the manuals that document this code

75,000+ service documents · 20,000+ error codes · 100+ brands

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