What does the Alpha 71 fault code mean?

Your boiler is failing to heat the water inside it, so it has shut down to prevent damage while it fails to warm up your radiators or taps.

How much does it cost to fix Alpha error code 71?

Typical repair cost for the Alpha 71 fault is £150-300 including labour.

From ignition the boiler detects no temperature rise in the primary circuit

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Almost always a stuck diverter valve on combis.

Each noise points to a different fault.

Sludge build-up — needs flushing, not bleeding.