Error code reference

Samsung Heat Pump Error Code E321

SUMP TEMP DIGITAL sensor error OPEN/SHORT (detected when outdoor temp over -10°C; over 4.95V/-30°C or below 0.5V/151°C).

SourceSamsung Heat Pump - Service Manual: Troubleshooting & Error Codes (AVMWH020CA0G)p. 220, 250

Samsung codes Samsung heat pump codes

Diagnostic procedure

The full E321 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

First diagnostic step

Check if sensor connector is separated from PCB; measure resistance across terminals.

SourceSamsung Heat Pump - Service Manual: Troubleshooting & Error Codes (AVMWH020CA0G)p. 220, 250

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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

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

Models covered by the manuals that document this code

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The full E321 procedure

Where this code is documented

Models covered by the manuals that document this code

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