Error 42 — Open high pressure switch

What does 42 mean?

The high pressure switch circuit has been detected as open for 30 seconds after 3 minutes of compressor runtime. This error locks if it happens 3 times in 1 hour.

• Incorrect pressure switch wiring
• Abnormal system pressure
• System is clogged
• Incorrect refrigerant charge
• Bad valve
• Pressure switch is bad
• PCB is bad

Click steps to track your progress.

1. 1

   Power off and check if the pressure switch connection is okay.

2. 2

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

3. 3

   Check if the EEV coil is fully seated and reconnect it.

4. 4

   Open the service valve and check if the piping system is clogged or if the connection pipe is bent.

5. 5

   Replace the pressure switch if it is bad. Replace the sensor if it is bad.