H3
Mitsubishi Electric Humidifier Overflow / Leak Detection

Humidifier error H3; unit stops humidifying and may beep.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Blocked humidifier drain, cracked humidifier tray, faulty overflow sensor, mis‑seated humidifier tank

How to Fix / Troubleshooting

Safety: Unplug the unit. Place towels under the appliance to catch any water.

Steps:

  • Inspect for leaks: Remove the front cover and check around the humidifier tray for standing water.
  • Clean drain: Locate the small drain outlet from the humidifier tray to the main tank or drain hose. Clear any slime or scale with a soft brush and warm water.
  • Check tray: Remove the tray and inspect for cracks. Replace the humidifier tray if damaged.
  • Overflow sensor: Clean and test the overflow float or electrodes. Replace the overflow sensor if it falsely detects overflow.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Humidifier Tray / Overflow Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements