Hitachi Yutaki M & Yutaki S fault 03

Lost communication with all sub YUTAKI units

Heat pump

What it means

Communication with all Sub YUTAKI Units has been lost.

Likely causes

  1. Loose connector
  2. Disconnected connector
  3. Broken connector
  4. Short-circuited connector

Where to start

  1. Check communication wiring/connectors to all slave units
  2. Check communication connector for looseness, disconnection, breakage or short-circuit
  3. Access Menu > Operation Information to view General system data: operation status, water setting temperature, outdoor ambient temperature, outdoor ambient 2 temperature, outdoor ambient average temperature, second ambient average temperature, 24h average temperature.

The full answer, free

  • 7 more checks in order
  • The readings and component tests from the manual
  • How to put it right, step by step
  • The manual page for this fault (page 336), right under the answer

Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.

From the Hitachi manual for the Yutaki M & Yutaki S. Check the model on the data plate before you order parts.

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