What does the Ferroli F43 fault code mean?

Your boiler has stopped itself from overheating because the water isn't moving around the system properly or there is an air pocket trapped inside.

How much does it cost to fix Ferroli error code F43?

Typical repair cost for the Ferroli F43 fault is £100-£350 including labour.

Check that your system pressure is between 1 and 1.5 bar on the gauge

Exchanger protection intervention – could be because no system water circulation or there’s air in the system

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.

Lockout fault with a reset-needed pattern.

Sludge build-up — needs flushing, not bleeding.