L5
Daikin Lockout Due to Repeated Overcurrent / Protection Trips

Daikin furnace shows L5; unit may lock out on repeated overcurrent or protection events.

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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.

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Possible Causes

Persistent short or overload on blower or inducer motor, Repeated E5 or L3 events not resolved, Faulty Daikin control board protection circuit, Incorrect fuse or breaker size feeding furnace

How to Fix / Troubleshooting

Safety: Do not continue resetting the system without finding the cause. Turn off power and contact a professional if you are not trained in electrical diagnostics.

Steps to check:

  • Review prior faults: Note any previous error codes (E5, L3, etc.) that occurred before L5. These indicate which circuit is causing the lockout.
  • Inspect motors and wiring: Check blower and inducer motors for overheating, burnt smell, or damaged wiring.
  • Check fuses: Inspect any onboard fuses on the Daikin PCB. Replace only with the same type and rating if blown, and investigate why it blew.

L5 indicates a serious, unresolved fault. A qualified technician should perform detailed current and insulation resistance tests and replace the defective motor or control board.

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Repair Difficulty

Professional Required 5/5

Required Part

Daikin Furnace Main Control Board or Motor (as diagnosed)
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