What does the Halstead 0001 fault code mean?

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent any damage to the internal components.

How much does it cost to fix Halstead error code 0001?

Typical repair cost for the Halstead 0001 fault is £150-300 including labour.

Overheat protection: flow and return thermostats monitor abnormal temperatures

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.

Safety-critical — turn off, read this.