Search

Home › Mitsubishi Electric › Air Conditioners › U9 / UH

Mitsubishi Electric Air Conditioner U9 / UH Error Code

Power supply or current sensor problem. What it means, which models show it, and how to clear it, easiest fix first.

Mitsubishi ElectricAll Mitsubishi Electric air conditioner codes

U9 / UH
May need a pro

The outdoor unit has detected a supply voltage outside its normal range, a fault in the signal it uses to time its power circuit, or a current sensor that isn't working.

Compatible models

Mitsubishi Electric doesn't publish a model list for this code; it appears on Mitsubishi Electric air conditioners with a digital display. Check your owner's manual.

Also shown as

Meanings can vary by outdoor unit series; check your manual.

Difficulty

Try the basic checks, but the usual fix is a technician's job.

Safety first: unplug the air conditioner (or switch off its breaker) before touching filters, hoses or panels. If you smell burning or gas, or see water near the outlet, stop and call a professional.

How to fix Mitsubishi Electric U9 / UH

  1. Check the breaker

    Make sure the breaker for the outdoor unit is fully on. If it trips again when reset, leave it off.

  2. Reset the power at the breaker

    Switch off the breaker that feeds the air conditioner (some systems have separate breakers for the indoor and outdoor units, so switch off both). Wait about five minutes, switch the power back on and restart the unit to see if the code clears.

When to call a technician

If the code returns, have a technician or electrician check the supply and the outdoor electronics.

Parts linked to U9 / UH

These are the parts most often behind this code. Tap one to see what it does and the signs it is failing.

Order parts by your full model number so they fit.

Frequently asked questions

What does U9 / UH mean on a Mitsubishi Electric air conditioner?

The outdoor unit has detected a supply voltage outside its normal range, a fault in the signal it uses to time its power circuit, or a current sensor that isn't working.

Which Mitsubishi Electric models show the U9 / UH code?

Mitsubishi Electric doesn't publish a model list for this code; it appears on Mitsubishi Electric air conditioners with a digital display. Check your owner's manual.

Can I fix Mitsubishi Electric U9 / UH myself?

Only the basic checks. You can safely try the steps above, but U9 / UH usually points to a part or fault that needs a technician.

What if U9 / UH keeps coming back?

A code that returns after a reset and the checks above usually means a part is wearing out. Note when U9 / UH appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.

Other Mitsubishi Electric air conditioner codes

Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.

Sources we checked