What does the Alpha 03 fault code mean?

Your boiler has detected that the exhaust gases are getting too hot and has automatically shut itself down to prevent damage.

How much does it cost to fix Alpha error code 03?

Typical repair cost for the Alpha 03 fault is £120-250 including labour.

Flue thermostat operated

This is a emergency 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.