CodeRegistry
Brands
  1. Home
  2. MHI
  3. Air Conditioning
  4. 1
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.

1

OPERATION INDICATOR lamp blinks 1 time (Pattern A) - Indoor/outdoor unit communication error (Transmitting error - Outdoor unit)

MHI · Air Conditioning

What does 1 mean?

The OPERATION INDICATOR lamp blinks once in 'Output pattern A' from the indoor unit, indicating a communication issue between the indoor and outdoor units, specifically a transmitting error from the outdoor unit.

Common Causes

  • Indoor/outdoor unit communication error (transmitting error from outdoor unit).

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check if the indoor/outdoor connecting wire is properly connected.

  2. 2

    Verify that no noise is interfering with the indoor/outdoor connecting wire or power supply.

  3. 3

    Re-check the error by turning off the main power supply, waiting a few moments, and then turning it back on.

Browse all codes in this manual (124)
Verified technical data. Last updated: April 2026

Related Faults

00Outdoor Board LED only green lights up after startup - No outdoor unit of address 0 / Remote controller transmission wire open14OPERATION INDICATOR lamp blinks 14 times (Pattern A) - Other errors2OPERATION INDICATOR lamp blinks 2 times (Pattern A) - Open/short of outdoor unit thermistors
Source: MHI Air Conditioning
Open Manual (Page 23)Search more codes in this manual