P4 - 4 red flashes, 2 green flashes — Drain sensor fault

What does P4 mean?

This error indicates an issue with the drain sensor (DS), reporting an open or short circuit. This sensor monitors the condensate drain.

• Drain sensor (DS) is disconnected
• Drain sensor has an open circuit
• Drain sensor has a short circuit
• Faulty sensor or wiring

Click steps to track your progress.

1. 1

   Verify that the drain sensor is securely connected.

2. 2

   Check the wiring leading to the drain sensor for any damage.

3. 3

   Test the continuity and resistance of the drain sensor.

4. 4

   If the sensor is faulty, it will need to be replaced.