What does the Grant Overheat fault code mean?

Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent any internal damage.

How much does it cost to fix Grant error code Overheat?

Typical repair cost for the Grant Overheat fault is £150-350 including labour.

Heat exchanger exceeds a pre-set temperature of 111°C ± 3°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.

Each noise points to a different fault.

Work through these before the call-out.

Sludge build-up — needs flushing, not bleeding.