Trianco High Temperature Air Source Heat Pump R290 fault F06

DC bus under voltage

Heat pump

What it means

DC bus under voltage protection.

Likely causes

  1. Compressor Issue
  2. Fan not running or speed is too low
  3. Refrigerant leak
  4. Loose screws
  5. Fan blade or motor issue
  6. Touching components
  7. EEV step is not suitable
  8. Refrigerant amount incorrect
  9. Parameter Issue

Where to start

  1. Check the voltage between DCP-IN and DCN-IN if lower than 300V, it will get this protection
  2. Check the input voltage of R/S/T on compressor driver board if lower than 210V, it will get this protection
  3. If they are OK, please replace a new compressor driver board

The full answer, free

  • 17 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 35), 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 Trianco manual for the High Temperature Air Source Heat Pump R290. Check the model on the data plate before you order parts.

Other Trianco High Temperature Air Source Heat Pump R290 fault codes