CodeRegistry
Brands
  1. Home
  2. Mitsubishi Electric
  3. MSZ-AP Air Conditioners
  4. Upper lamp 2-time blink
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.

Upper lamp 2-time blink

Operation Indicator Lamp 2 Blinks - Room Temp / Indoor Coil Thermistor Trouble

Mitsubishi Electric · MSZ-AP Air Conditioners

What does Upper lamp 2-time blink mean?

The upper lamp of the indoor unit's Operation Indicator blinks twice in a pattern. This indicates a problem with either the room temperature thermistor or the indoor coil thermistor, which are critical for accurate temperature sensing.

Common Causes

  • Trouble with the room temperature thermistor.
  • Trouble with the indoor coil thermistor.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn OFF the main power supply to the air conditioner.

  2. 2

    Ensure the indoor unit's air intake and output are not blocked by furniture or curtains, as this can affect temperature readings.

  3. 3

    Verify that the remote controller's temperature setting is appropriate for the room.

  4. 4

    Turn the main power supply back ON. If the problem persists, contact a qualified service technician to inspect and potentially replace the thermistors.

Browse all codes in this manual (87)
Verified technical data. Last updated: April 2026

Related Faults

3 Min Restart DelayUnit cannot be operated for about 3 minutes after restart - Microprocessor protection3 Short Beeps3 short beeps from indoor unit - Weekly timer setting failedAP Mode activatedNET and MODE LEDs flashing (every 5 seconds) - Access Point Mode activated
Source: Mitsubishi Electric MSZ-AP Air Conditioners
Open Manual (Page 32)Search more codes in this manual