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Mitsubishi Electric Air Conditioner E6 / E7 / E9 Error Code

Indoor and outdoor units aren't communicating. What it means, which models show it, and how to clear it, easiest fix first.

Mitsubishi ElectricAll Mitsubishi Electric air conditioner codes

E6 / E7 / E9
May need a pro

The indoor and outdoor units have lost their communication link. A tripped outdoor breaker, a damaged or loose interconnecting cable, or a fault on either unit's board can cause it.

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

E6 and E7 are reported by the indoor unit; E9 is the same type of fault detected by the outdoor unit. Mitsubishi Electric's North American controller manual groups the whole E6 to EF range as indoor/outdoor communication errors. Some outdoor units use E6 for a different fault (a compressor protector opening), so 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 E6 / E7 / E9

  1. Check both breakers

    Make sure the breakers for the indoor and outdoor units are on. A tripped outdoor breaker is the simplest cause.

  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 persists, a technician needs to check the interconnecting cable and boards. On a new system, contact the installer.

Parts linked to E6 / E7 / E9

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 E6 / E7 / E9 mean on a Mitsubishi Electric air conditioner?

The indoor and outdoor units have lost their communication link. A tripped outdoor breaker, a damaged or loose interconnecting cable, or a fault on either unit's board can cause it.

Which Mitsubishi Electric models show the E6 / E7 / E9 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 E6 / E7 / E9 myself?

Only the basic checks. You can safely try the steps above, but E6 / E7 / E9 usually points to a part or fault that needs a technician.

What if E6 / E7 / E9 keeps coming back?

A code that returns after a reset and the checks above usually means a part is wearing out. Note when E6 / E7 / E9 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