Trianco High Temperature Air Source Heat Pump R290 fault E03

Water flow switch protection

Heat pump

What it means

Water flow switch protection indicating insufficient or absent water flow detected.

Likely causes

  1. Water pump failure
  2. The water circuit filter is dirty and blocked
  3. The water flow switch is false connected or damaged

Where to start

  1. Check Water Flow reading to confirm flow rate is present
  2. Check Coil Temp reading for refrigerant coil condition
  3. Check Low Pressure reading against expected refrigerant circuit pressure

The full answer, free

  • The readings and component tests from the manual
  • How to put it right, step by step
  • The manual page for this fault (page 34), 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