Error 151 — Opened EEV of indoor unit (2nd detection)

What does 151 mean?

The Electronic Expansion Valve (EEV) in the indoor unit is detected as being open when it should be closed or regulating. This is a confirmed issue, preventing proper refrigerant control.

• Malfunctioning EEV valve
• Control board issue affecting EEV operation
• Refrigerant pressure imbalance
• Faulty EEV motor or sensor

Click steps to track your progress.

1. 1

   Power off the entire HVAC system at the main circuit breaker.

2. 2

   Wait for a few minutes (at least 5-10 minutes) for the system to fully reset.

3. 3

   Restore power and observe if the error clears and the system operates normally.

4. 4

   If the error persists, there may be a mechanical or electrical fault with the EEV or its control.

5. 5

   This issue typically requires diagnosis and repair by a certified HVAC technician.