Error 42 — Open high pressure switch

What does [42] mean?

The high pressure switch circuit has been detected as open for 30 seconds after 5 minutes of compressor run time. This indicates a potential issue with system pressure or the switch itself.

• Incorrect pressure switch wiring.
• Abnormal system pressure.
• The system is clogged.
• Incorrect refrigerant charge.
• A valve is malfunctioning.
• The pressure switch is faulty.
• The main control board (PCB) is faulty.

Click steps to track your progress.

1. 1

   Power off the unit and check if the pressure switch connection is secure.

2. 2

   Use a multimeter to check if the high pressure switch terminal is short-circuited.

3. 3

   Check if the Electronic Expansion Valve (EEV) coil is fixed well.

4. 4

   Ensure the stop valve is open.

5. 5

   Use a multimeter to check the resistance of Tc & Te.

6. 6

   Inspect the piping system for clogs and clean if necessary.