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Drain Clogging

Drainage Clogged or Defective — Water overflow or poor drainage

Mitsubishi Heavy Industries · Packaged Air Conditioners

What does Drain Clogging mean?

The drain system collects and expels condensation from the unit. If the drain pan or pump becomes clogged with foreign matter or dirt, water may not drain properly, leading to leaks or system malfunction.

Common Causes

  • Accumulation of dirt, slime, or foreign objects in the drain pan or pump
  • Blockage in the drain line, such as debris or a kink
  • Drain pump malfunction or dirt buildup causing drainage defect

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Visually inspect the drain pan for standing water, dirt, or foreign objects.

  2. 2

    Carefully clean any visible dirt or debris from the drain pan and around the drain outlet.

  3. 3

    Ensure the external drain line is not kinked or visibly obstructed.

  4. 4

    If the problem persists, contact a qualified service technician to inspect the drain pump and internal lines.

Browse all codes in this manual (21)
Verified technical data. Last updated: April 2026

Related Faults

Abnormal Compressor NoiseCompressor Making Abnormal Sound or Vibrating — Indicates a serious internal issueAbnormal DisplayAbnormal Display on Electric Component Box/Control Panel — Indicates an electrical issueAbnormal Fan NoiseFan Making Abnormal Sound or Vibrating — Indicates an internal issue
Source: Mitsubishi Heavy Industries Packaged Air Conditioners
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