CodeRegistry
Brands
  1. Home
  2. Mitsubishi Heavy Industries
  3. Air Conditioners
  4. E42 / Outdoor Red LED 1 flash
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

E42 / Outdoor Red LED 1 flash

Error E42 / Outdoor Red LED Flashes Once — Abnormally high current in compressor

Mitsubishi Heavy Industries · Air Conditioners

What does E42 / Outdoor Red LED 1 flash mean?

Error E42, indicated by one flash of the outdoor unit's red LED, means an abnormally high current has been detected in the compressor. This is a serious electrical fault that can damage the compressor.

Common Causes

  • Abnormally high current detected in compressor

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Immediately turn off the main power supply to the air conditioner.

  2. 2

    Do not attempt to restart the unit.

  3. 3

    This issue indicates a severe electrical or mechanical problem with the compressor.

  4. 4

    Contact a qualified HVAC technician or electrician without delay for professional diagnosis and repair.

Browse all codes in this manual (110)
Verified technical data. Last updated: April 2026

Related Faults

01Power source faulty — RUN LED OFF, TIMER LED flashes 1 time05Wired remote control wiring error — RUN LED OFF, TIMER LED flashes 5 times35Cooling high pressure control activated — RUN LED flashes 3 times, TIMER LED flashes 5 times
Source: Mitsubishi Heavy Industries Air Conditioners
Open Manual (Page 4)Search more codes in this manual