Daikin U2: power supply malfunction or an instantaneous power failure

What Does Error U2 Mean?

In the Daikin malfunction chart, U2 belongs to the system division and reads as a malfunction of the power supply or an instantaneous power failure. That covers both a supply that briefly disappeared and a supply that is present but outside what the drive will work with, which is why one U2 after a storm and a U2 that repeats every day mean unrelated things. Applies to: Daikin equipment covered by the SM-TS3 malfunction chart, where the U division reports system-level conditions across room air, SkyAir, and VRV The reading is taken from the Daikin After Sales Service chart, where the U division covers system conditions rather than one unit. Some Daikin equipment, including the room air lines, presents a related shortage entry as U0, so confirm which digit is displayed before treating the fault as electrical. Owner-safe checks: Check whether a power cut, a storm, or electrical work coincided with the code, and write down what you find. | Confirm that the dedicated isolator and any protective device serving the equipment are in their normal operating position. | Read the supply voltage and frequency printed on the outdoor unit data plate so the figures are available to service. Qualified technician: Measuring supply voltage under load, inspecting isolator and terminal connections, and testing the drive input are qualified electrical tasks. | A protective device that operates repeatedly, a burning smell, or heat at an isolator is a stop condition. Leave the supply off and arrange an electrical inspection.