What it means
Mitsubishi's code tables call it 'compressor overcurrent interruption'. In the PUZ-HA manual UP is overcurrent after the compressor has run for 30 seconds, and UF is the related code for overcurrent within the first 30 seconds. With a wireless remote, the self-check reports UP as 2 beeps and 2 flashes in the outdoor-fault pattern. On MSZ wall units, repeated compressor overcurrent stops show as 5 blinks ('outdoor power system').
What to check, in order
- Clear the airflow
Mitsubishi lists short cycling of air at the indoor or outdoor unit as a cause. Move anything that blocks the indoor unit's air inlet or outlet, or the air around the outdoor unit.
- Switch off and on once
Turn the system off at the breaker or isolator and back on. If UP returns, leave it off and book a repair.
When to call an engineer
Call an F-gas certified engineer (UK) or HVAC technician (US). Mitsubishi lists a closed stop valve, a drop in supply voltage, loose, disconnected or swapped compressor wiring, a faulty indoor or outdoor fan, short cycling, a control board fault and a faulty compressor.
A repair visit will usually check the compressor, its wiring and the inverter board that drives it.
- Note the model and serial number. They're on a label on the side of the indoor unit, and on the outdoor unit.
- Write down the exact code, and what the appliance was doing when it appeared.
- Check whether it's still under warranty. If it is, the repair may cost you nothing.
Quick answers
What does the Mitsubishi UP error code mean?
The outdoor unit cut power to the compressor because it was drawing too much current. Mitsubishi's code tables call it 'compressor overcurrent interruption'. In the PUZ-HA manual UP is overcurrent after the compressor has run for 30 seconds, and UF is the related code for overcurrent within the first 30 seconds. With a wireless remote, the self-check reports UP as 2 beeps and 2 flashes in the outdoor-fault pattern. On MSZ wall units, repeated compressor overcurrent stops show as 5 blinks ('outdoor power system').
Can I fix Mitsubishi UP myself?
Engineer only (engineer visit). Start with: clear the airflow; switch off and on once. Call an F-gas certified engineer (UK) or HVAC technician (US). Mitsubishi lists a closed stop valve, a drop in supply voltage, loose, disconnected or swapped compressor wiring, a faulty indoor or outdoor fan, short cycling, a control board fault and a faulty compressor.
Is Mitsubishi UP worth repairing?
Get a quote first. Causes range from a closed valve or a poor power supply to a failing compressor. Get a diagnosis and a quote before agreeing to major work.
Checked against
- Mitsubishi Electric SLZ-KF09/12/15/18NA1 ceiling cassette (M-series) Technical & Service Manual TCH118A (PDF)
- Mitsubishi Electric SLZ-M15-60FA ceiling cassette Technical & Service Manual OCH522 (PDF)
- Mitsubishi Electric SUZ-M25-71VA outdoor unit Technical & Service Manual OCH684A (PDF)
- Mitsubishi Electric PUZ-HA30/36NHA4 outdoor unit Service Manual OCH504 (PDF)
- Mitsubishi Electric MSZ-FH06-18NA(2) indoor unit Service Manual OBH683E (PDF)
Last reviewed October 2026. Manufacturers update their pages, and your manual is the final word. Spotted a mistake? Email contact@appliance-error-codes.com.