What does the Alpha 02 fault code mean?

Your boiler has automatically turned itself off because it has become too hot inside, likely due to a lack of water flow.

How much does it cost to fix Alpha error code 02?

Typical repair cost for the Alpha 02 fault is £120-250 including labour.

Overheat thermostat operated

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.

Almost always a stuck diverter valve on combis.

Sludge build-up — needs flushing, not bleeding.