E17

Keston Fan Speed / Tachometer Fault

Boiler shows E17, fan speed appears abnormal or noisy

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.

Possible Causes

Faulty fan speed sensor, Fan bearings worn, PCB fan control fault, Obstructed fan impeller

How to Fix / Troubleshooting

Safety: Isolate power and gas. Do not run the boiler with a noisy or failing fan.

User checks:

Listen for unusual grinding or whirring noises from the boiler when it attempts to start. Report these to the engineer.

Engineer checks:

Inspect the Keston fan assembly for free rotation and absence of play in the bearings; replace if noisy or stiff.
Check the fan tachometer/speed feedback wiring to the PCB for damage or loose connectors.
Monitor fan speed via diagnostic mode (if available) and compare with target values.
If the fan is mechanically sound but speed control is erratic, suspect and test the main PCB.

Repair Difficulty

Hard 4/5

Required Part

Flue Fan Assembly

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