What does the Ideal 4 / F fault code mean?

Your boiler has shut itself down because it detected that the water inside has become dangerously overheated.

How much does it cost to fix Ideal error code 4 / F?

Typical repair cost for the Ideal 4 / F fault is £150-300 including labour.

Temperature safety sensor above 101 °C.

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

Almost always a stuck diverter valve on combis.

Each noise points to a different fault.

Work through these before the call-out.