What does the Keston E00 fault code mean?

Your boiler thinks a flame is burning even though it hasn't been told to light yet, which stops it from starting up for safety reasons.

How much does it cost to fix Keston error code E00?

Typical repair cost for the Keston E00 fault is £120-280 including labour.

Flame detected when not expected – check boiler earth and probe condition

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

Lockout fault with a reset-needed pattern.

Safety-critical — turn off, read this.

7 signs repair isn't worth it anymore.