A3

Daikin Drain Level Error / Drain Pump Fault

Daikin indoor unit stops and may leak water; controller shows A3

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.

Possible Causes

Clogged condensate drain line, Blocked or dirty drain pan, Failed or jammed internal drain pump (for cassette/ducted units), Faulty drain pump float switch

How to Fix / Troubleshooting

Safety first: Turn off power before working on the indoor unit or drain system.

Steps:

Remove filters and access the drain pan. Mop up any standing water with towels.
Inspect the drain outlet and hose for slime, algae, or debris; clean thoroughly.
Use a wet/dry vacuum at the drain outlet outside to pull out blockages.
On cassette or ducted units with a drain pump, listen for pump operation when the unit starts; if silent, the pump may have failed.

Technician tasks:

Test the drain pump by applying power directly (if safe and per manual) and checking for operation.
Check the float switch continuity and operation.
Replace the drain pump assembly or float switch if defective.

Repair Difficulty

Medium 3/5

Required Part

Drain Pump Assembly

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