Code 33-15 Compressor Low Discharge Shutdown — Compressor discharge pressure is too low

What does 33-15 mean?

The compressor's discharge pressure has dropped below the lower safe operating limit for a period of time, causing the system to shut down. This fault applies to 5-ton models. Repeated occurrences can lead to a lockout (Code 33-55).

• Malfunctioning reversing valve.
• Low refrigerant charge.
• Missing or stuck TXV/EXV (Thermostatic/Electronic Expansion Valve).
• Compressor not operating properly.

Click steps to track your progress.

1. 1

   Check the system's operational parameters using the service app (technician step).

2. 2

   Inspect the reversing valve for proper function.

3. 3

   Verify refrigerant charge levels (technician step).

4. 4

   Check the TXV/EXV for proper operation (technician step).