EF (1508) - 4-way valve trouble in heating mode

What does EF mean?

There is an issue with the 4-way valve, which is responsible for switching between heating and cooling modes, specifically when the Mitsubishi Electric PUMY Air Conditioner is in heating mode. The system will stop operating.

• Malfunction of the 4-way valve itself
• Electrical fault or poor connection to the valve
• System refrigerant issues affecting valve operation

Click steps to track your progress.

1. 1

   Note the error code displayed on the remote controller or outdoor unit.

2. 2

   Power off the Mitsubishi Electric PUMY Air Conditioner system at the main electrical breaker.

3. 3

   Wait for at least 30 seconds, then restore power to the system.

4. 4

   If the error persists, contact a qualified service technician for diagnosis and repair of the 4-way valve.