Hitachi Yutaki M & Yutaki S fault 106

What it means

Triggered when discharge gas temperature Td ≥ 120 ºC continued for 10 minutes, or Td ≥ 140 ºC continued for 5 seconds.

Likely causes

1. Overheating of discharge gas
2. Built-in sensor reading differs from actual ambient room temperature due to sensor location or controller self-heating

Where to start

1. Confirm unit is capable of heating and cooling, and cooling operation is enabled, before this function is available
2. Check Status is enabled for Auto Heat/Cool
3. Verify Switch to Heat Temperature setting (switches to heating when outdoor temp falls below threshold)