What does the Ariston A03 fault code mean?

Your boiler has detected that the water inside it has become dangerously hot and has shut itself down to prevent damage or safety risks.

How much does it cost to fix Ariston error code A03?

Typical repair cost for the Ariston A03 fault is £120-250 including labour.

The output temperature exceeds 105°C during operation

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.

Sludge build-up — needs flushing, not bleeding.

Safety-critical — turn off, read this.