What does the Vaillant F.24 fault code mean?

Your boiler is struggling to move water through the system, which is causing it to stop running to prevent overheating.

How much does it cost to fix Vaillant error code F.24?

Typical repair cost for the Vaillant F.24 fault is £180-450 including labour.

Check if the pressure gauge is between 1 and 1.5 bar and top up if low

Low water / Pump Failure / Blockage

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Each noise points to a different fault.

Sludge build-up — needs flushing, not bleeding.

Six most common causes of dropping pressure.