Error 43 — Low pressure switch circuit is open

What does [43] Open low pressure switch mean?

The low pressure switch circuit has been detected as open for 60 seconds after the compressor has been running for 3 minutes, or open for 30 seconds while the system is in standby.

• Incorrect pressure switch wiring
• Abnormal system pressure
• System is clogged
• Incorrect refrigerant charge
• Faulty valve
• Faulty pressure switch
• Faulty PCB

Click steps to track your progress.

1. 1

   Check if the pressure switch wiring connection is okay.

2. 2

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

3. 3

   Ensure the Electronic Expansion Valve (EEV) coil is fully seated.

4. 4

   Check if the service valve is open.

5. 5

   Short the high pressure switch terminal on the PCB to see if the system reports a failure.

6. 6

   Check if the piping system is clogged.