Mitsubishi Error Code 4: Inverter Error

LED Blink Pattern

How to Fix Mitsubishi Code 4

1. Step 1: Turn off your HVAC system at the thermostat and the circuit breaker.
2. Step 2: Check and replace your air filter if it's dirty.
3. Step 3: Call a professional HVAC technician to diagnose and repair the issue.

How to Reset Mitsubishi Code 4

1. Turn off the unit using the remote control or wall controller.
2. Turn off the circuit breaker for the outdoor and indoor units. Wait 60 seconds.
3. Restore power at the breaker.
4. Turn the unit on with the remote control. If the error returns, the fault needs professional diagnosis.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Mitsubishi Error Code 4 Mean?

The Mitsubishi 4 error indicates a problem with your system's inverter, which controls the speed of the compressor. This error can be caused by a variety of issues, but it's important to note that it's not an immediate safety hazard. However, it's crucial to address this issue promptly to prevent further damage to your system.

Common Causes

• Faulty inverter board
• Low refrigerant level
• Dirty or clogged filter
• Wiring issues or poor electrical connection

Diagnostic Steps

Replacement Parts

Related Codes on Same Models

Other codes that affect the same Mitsubishi model families as 4.