Why Is My Daikin Air Conditioner Not Turning On?

If your Daikin air conditioner won’t turn on, take a deep breath – there could be several reasons for it, ranging from simple fixes to more challenging ones. HVAC.com discusses common Daikin AC troubleshooting tips if your system suddenly stops working to ensure you stay cool and comfortable all summer long.

Troubleshooting Why Your Daikin Air Conditioner Won’t Turn On

1. Check the Power Supply

The first step in troubleshooting any appliance that won’t turn on is to ensure it’s receiving power. Start by checking if the circuit breaker has tripped. If you reset the breaker and it continues to trip, there could be an electrical issue that requires a professional.

The next step is to inspect the switch on the indoor components and the switch to your condenser unit (it’s usually on the exterior wall near the unit). Make sure both are in the “on” position.

2. Test the Thermostat

A thermostat issue can also cause your Daikin air conditioner to stop working. Check that the thermostat is set to “cool”, and the temperature is lower than the room’s current temperature. If you have a programmable thermostat, double-check the schedule to make sure it hasn’t been set to a different mode or time.

A dead thermostat battery can also cause your Daikin AC to appear unresponsive. If the thermostat is non-responsive even after you change the batteries, it might need repair or replacement.

3. Check the Air Filter

If the air filter is clogged with dirt and debris, your unit can struggle to operate efficiently or turn on at all. Regularly cleaning or replacing your air filter can prevent this issue from occurring in the future.

4. Inspect the Condensate Drain Line

Daikin air conditioners often have a safety feature that stop it from operating if the condensate drain is clogged to avoid water damage from overflowing. If you notice standing water or an obstruction in the AC drain line, carefully clear the clog or contact a professional.

5. Reset the AC Unit

Resetting the air conditioner can cause your Daikin unit to start working again. Turn off the power to the unit, either at the thermostat or the circuit breaker, wait a few minutes, then turn it back on. This process can reset any minor electronic glitches that might be causing the problem.

Malfunctions That Can Prevent Your Daikin Air Conditioner from Turning On

System malfunctions could be preventing your Daikin air conditioner from powering up, including:

Faulty Capacitors

Capacitors start and run the air conditioner’s motors. If the capacitor fails, the motor might not start, causing your AC to remain off. Signs of a faulty capacitor include a clicking noise when you try to turn on the unit or visible swelling on the capacitor itself.

Defective Contactors or Relays

Contactors and relays are electrical switches that control the flow of power to different components of your air conditioner. If they become worn out or stuck, the power supply can be disrupted, preventing your air conditioner from turning on.

Broken or Burned Wires

Electrical wiring issues are another common reason your Daikin air conditioner may not turn on. Wires can become damaged due to age, pests, or overheating. If you see burned or frayed wires, or if the AC unit seems to lose power randomly, contact a qualified HVAC contractor as this issue can potentially become a fire hazard.

Malfunctioning Compressor

If the outdoor compressor fails, the entire system won’t function. A malfunctioning compressor might make a humming or buzzing noise without the AC turning on, or it might overheat and shut down.

Faulty Fan Motors

Your Daikin air conditioner relies on fan motors to circulate air. If the fan motor suddenly stops working properly, the system may not turn on, or it'll shut down suddenly. Symptoms of a faulty fan motor include squeaking or grinding noises and reduced airflow.

Issues with the Control Board

Your air conditioner’s control board manages various functions and settings. A damaged or defective board may cause the system to malfunction or not turn on at all. An HVAC contractor can determine whether to repair or replace the control board.

If you’ve tried the troubleshooting steps above and your Daikin air conditioner still won’t start up, contact a licensed HVAC technician to repair your system and restore it to proper working order.