What does the Alpha E43 fault code mean?

Your boiler is struggling to keep a flame lit and has locked itself out for safety after several failed attempts.

How much does it cost to fix Alpha error code E43?

Typical repair cost for the Alpha E43 fault is £100-300 including labour.

Check that your gas emergency control valve is in the 'on' position

Loss of flame signal too many times

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.

Older boilers — thermocouple, draught, gas supply.

Safety-critical — turn off, read this.