Dehumidifier shows P3 and will not start the compressor.

Note: P3 is often a protective indication rather than a hardware failure.

• Verify room temperature: Use a separate thermometer to confirm the room is within the unit’s specified operating range (commonly 41–95°F / 5–35°C). If too cold, move the unit to a warmer area.
• Allow warm-up: If the unit was stored in a cold location, bring it indoors and let it sit unplugged for several hours to reach room temperature before use.
• Sensor check: If the room is warm but P3 persists, inspect the ambient temperature sensor and its wiring. A sensor reading artificially low can trigger P3.
• Replace sensor: Test the ambient sensor resistance and replace it if out of specification. If a new sensor does not resolve P3, the main PCB may be misreading and require replacement.