What does the Alpha 03 fault code mean?

Your boiler has detected that the exhaust gases leaving the system are dangerously hot and has shut itself down to prevent damage or overheating.

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

Typical repair cost for the Alpha 03 fault is £150-300 including labour.

High flue temperature - Flue sensor intervention (flue temperature too high)

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.

Lockout fault with a reset-needed pattern.

Sludge build-up — needs flushing, not bleeding.