Grant Aerona R290 fault E09

Outlet water temperature sensor failure (TB)

Heat pump

What it means

Outlet water temperature sensor (TB) failure due to incorrect connection, sensor failure, or faulty hydraulic PCB.

Likely causes

  1. The hydraulic PCB is faulty
  2. Wire disconnection or wiring error between the heat pump, wiring centre and touch screen display
  3. Fuse on the hydraulic module PCB may have failed
  4. Fuse on the Smart Controller wiring centre PCB may have failed

Where to start

  1. Check the hydraulic PCB
  2. Check wiring between heat pump, wiring centre and touch screen display
  3. Check fuse on hydraulic module PCB

The full answer, free

  • 1 more check 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 59), 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 Grant manual for the Aerona R290. Check the model on the data plate before you order parts.

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