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RUN light slow blink (3.5s ON, 0.5s OFF)

RUN light blinks slowly (3.5 seconds ON, 0.5 seconds OFF) — AUTO OFF operation during standby

MHI · Air Conditioning

What does RUN light slow blink (3.5s ON, 0.5s OFF) mean?

The green RUN light on the indoor unit will blink slowly in a pattern of 3.5 seconds ON and 0.5 seconds OFF. This indicates that the AUTO OFF operation is active while the unit is in standby.

Common Causes

  • AUTO OFF operation has been set and the unit is in standby.
  • Unit is preparing to automatically turn off.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify if AUTO OFF operation was intentionally set.

  2. 2

    Allow the unit to proceed with its scheduled AUTO OFF function.

  3. 3

    If unintended, refer to the manual to cancel AUTO OFF settings.

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 open1OPERATION INDICATOR lamp blinks 1 time (Pattern A) - Indoor/outdoor unit communication error (Transmitting error - Outdoor unit)14OPERATION INDICATOR lamp blinks 14 times (Pattern A) - Other errors
Source: MHI Air Conditioning
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