ErrorKhoj

Daikin Air Conditioner

Daikin AC L4 error

Inverter board / power module protection

Needs a technicianCross-checked from 2+ sources

Try a reset once. If it comes back, a trained technician should repair it.

What it means

The inverter drive (power module, DC voltage or heat sink) detected a fault and stopped the compressor.

Common causes

  • Voltage spike or unstable supply
  • Outdoor board overheating (poor air flow, very hot day)
  • Failed power module or board parts
  • Compressor wiring problem

Try this at home first

Tick each step as you go

When to call a technician

This needs a trained inverter technician. Users must never open boards or modules.

Safety first

Always switch off at the wall socket or MCB before touching any part. Do not open the outdoor unit, control boards or gas pipes yourself — they carry high voltage and pressure.

Frequently asked questions

What does L4 mean on a Daikin Air Conditioner?

Inverter board / power module protection. The inverter drive (power module, DC voltage or heat sink) detected a fault and stopped the compressor.

Can I fix Daikin Air Conditioner error L4 myself?

You can try a reset first: Switch off at the MCB for 10–15 minutes. If the code returns, call a technician.

Is it safe to keep using the Air Conditioner with L4?

Avoid repeated restarts; running with this fault can cause more damage.

Other Daikin AC codes

H6 Compressor start / rotation fault H8 Current sensor (CT) fault H9 Outdoor air temperature sensor fault J3 Compressor discharge temperature sensor fault J6 Outdoor coil (condenser) temperature sensor fault L3 Inverter board / power module protection L5 Inverter board / power module protection P4 Inverter heat-sink temperature sensor fault U0 Low gas / refrigerant leak or blockage U2 Power supply voltage problem U4 Communication error (indoor ↔ outdoor unit) UA Indoor/outdoor mismatch or wrong wiring

All Daikin Air Conditioner error codes

Same code on other brands

L4 Current sensor (CT) faultBlue Star AC

Sources

We write every explanation in our own words from these references.

Last checked: 2026-10-20