Mitsubishi Heavy air conditioner error E12
Meaning
While trying to auto address, one or more of the units (either indoor or outdoor) is not set at 49
General meaning for the brand's models, unless a model's own manual says otherwise.
Meaning
One or more units (indoor or outdoor) are still addressed at 48 or 49 [factory setting]
General meaning for the brand's models, unless a model's own manual says otherwise.
Meaning
Auto address is not possible on the system you are commissioning (Auto address is only possible on a single KX2 system)
General meaning for the brand's models, unless a model's own manual says otherwise.
Meaning
Outdoor/Indoor communication error: units still addressed at 48 or 49, or auto address not possible on this system
General meaning for the brand's models, unless a model's own manual says otherwise.
Meaning
One or more units (indoor or outdoor) are still addressed at 40 or 49 (factory setting). Also: auto address not possible on this system
General meaning for the brand's models, unless a model's own manual says otherwise.
How the unit shows it
- Indoor circuit board Red LED: Flashes once
- Indoor circuit board Green LED: Keeps Flashing
- Outdoor circuit board Red LED: Stays Off
- Outdoor circuit board Green LED: Keeps Flashing
Causes and how to check
- 3 possible causes
- 2 checks in order
- the cited manual page, and follow-up questions
No account needed to look up codes.
Guides
- Communication error between indoor and outdoor unit: what to check, in which order
Communication (transmission) error codes usually come from the connecting wire, the supply or a board. The checks from easy to hard.