Error code reference

Heat Controller Air Conditioner Error Code 05

Communication error between indoor and outdoor units (displayed at indoor unit).

SourceHeat Controller Multi-Split Air Conditioner - Service Manual: Wall Mounted Systemsp. 72

Diagnostic procedure

The full 05 procedure

Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.

MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
Check input power AC 230V at both indoor and outdoor units; verify communication wires are correctly connected and resistance between communication line and GND is over 2MΩ.

SourceHeat Controller Multi-Split Air Conditioner - Service Manual: Wall Mounted Systemsp. 72

More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
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Where this code is documented

1 manual in the MyPros+ library documents this code for Heat Controller air conditioner.

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