F19
Saunier Duval Minimum power / low flow overheat fault

F19 error, often during low flow operation, water temperature too high

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

Flow rate below minimum specification, Scaled heat exchanger, Faulty flow sensor reading too high, Incorrect minimum gas setting

How to Fix / Troubleshooting

Safety first: Isolate power and allow the unit to cool.

Steps:

  • Increase flow: Open the hot tap fully and avoid using very low flow settings. Check and clean tap aerators and shower heads.
  • Check flow sensor: Ensure the Saunier Duval flow sensor turbine spins freely and is not partially blocked.
  • Descale: If the unit is old or in a hard water area, arrange for descaling of the primary heat exchanger.
  • Gas setting check: A technician should verify minimum burner pressure and adjust if necessary.

Warning: Very hot outlet water can cause scalding. Do not ignore this fault.

Advertisements

Repair Difficulty

Medium 3/5

Required Part

DHW Flow Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements