On Daikin air conditioners, error code U1 means: Power supply voltage out of range. Switch the unit off and try a power reset. If the code comes back, have it checked by a technician before using it again.
Can I keep using the air conditioner?
Switch the unit off and try a power reset. If the code comes back, have it checked by a technician before using it again.
Common causes
- Unstable mains power or a loose plug/socket
- Installation fault: wiring, unit combination or pipework
How to fix it
- Switch the unit off at the breaker for about 5 minutes, then switch it back on
- Plug directly into a wall socket (no extension lead) and check your power supply
- If the code returns, contact an authorised AC technician; don't open the unit yourself
Frequently asked questions
What does Daikin error U1 mean?
On Daikin air conditioners, error code U1 means: Power supply voltage out of range.
How do I fix Daikin error U1?
Start with these steps: Switch the unit off at the breaker for about 5 minutes, then switch it back on; Plug directly into a wall socket (no extension lead) and check your power supply; If the code returns, contact an authorised AC technician; don't open the unit yourself.
Can I keep using the air conditioner with error U1?
Severity: Medium. Switch the unit off and try a power reset. If the code comes back, have it checked by a technician before using it again.