A51
Ferroli DHW Flow Sensor / Turbine Fault

Ferroli furnace displays A51; may occur during DHW demand on combi-style units.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Stuck or scaled Ferroli DHW flow turbine, Faulty DHW flow sensor, Blocked inlet filter on cold water connection

How to Fix / Troubleshooting

Safety: Turn off power and close cold water inlet before opening any water components.

Steps:

  • Clean inlet filter: At the cold water inlet to the Ferroli unit, remove and clean the mesh filter of debris.
  • Check DHW flow sensor: Locate the flow sensor/turbine assembly. Remove it carefully and inspect for limescale or debris preventing rotation. Rinse and descale if necessary.
  • Reassemble and test: Refit the sensor, open the water valve, check for leaks, restore power, and run hot water to test.

Professional help: If A51 persists, the flow sensor or control board input may need replacement by a technician.

Advertisements

Repair Difficulty

Medium 3/5

Required Part

DHW Flow Sensor / Turbine
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements