Hitachi Yutaki M & Yutaki S fault 31

Incorrect capacity setting or combined capacity between outdoor and indoor units

Heat pump

What it means

System fault: incorrect capacity code setting or mismatch between outdoor and indoor unit capacities.

Likely causes

  1. Incorrect Capacity Code Setting
  2. Excessive or Insufficient Indoor Unit Total Capacity Code

Where to start

  1. Press right/left to switch between zones: Total, Space Heating, Space Cooling, DHW, Swimming Pool
  2. Press up/down to change comparison method: Today vs yesterday, This week vs past week, This year vs past year
  3. Navigate Menu > Energy Data > Input Power / Capacity / Reset Values

The full answer, free

  • 12 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 337), 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.

Other Hitachi Yutaki M & Yutaki S fault codes