Daikin Air Conditioner Error Code P1

P1 on a Daikin air conditioner indicates high voltage has been detected across capacitor C4 in the main inverter circuit, with a voltage waveform that matches an open phase condition on the power supply. This means the unit has sensed that one leg of the electrical supply may be missing or that a capacitor connection is faulty. The system shuts down to prevent damage to the inverter and compressor components.

No. The P1 fault indicates an abnormal voltage condition in the inverter circuit that can cause serious damage to the compressor, inverter board, and capacitor if the unit continues to operate. The system typically locks out to protect these components. Do not attempt to bypass the fault and continue running the unit until the underlying cause has been identified and corrected.

A power reset may temporarily clear the P1 error code, but if the underlying cause such as an open phase, a failed capacitor, or a loose connection is still present, the fault will return. Resetting without diagnosing and correcting the root cause risks further damage to the inverter components. Always resolve the fault condition before returning the unit to normal operation.

Some basic checks, such as verifying supply voltage at the disconnect and visually inspecting accessible wiring, can be done by a knowledgeable DIYer. However, working inside the inverter section of an air conditioner involves high voltages stored in capacitors that can be lethal even after power is disconnected. It is strongly recommended to have a qualified HVAC or electrical technician perform the internal inspection and any repairs.

Repair costs vary widely depending on the root cause. If the fix is simply reseating a loose capacitor connection or replacing a blown fuse, costs could be in the range of $75 to $200 for a service call. If capacitor C4, the inverter board, or supply-side components need replacement, costs can range from $300 to $1,000 or more depending on parts and labor rates in your area.