What does the Alpha 04 fault code mean?

Your boiler is struggling to detect the connection to the part that controls its gas supply, which prevents it from safely igniting.

How much does it cost to fix Alpha error code 04?

Typical repair cost for the Alpha 04 fault is £120-250 including labour.

Gas valve electrical connection fault - Gas valve wiring circuit fault detected

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

Older boilers — thermocouple, draught, gas supply.

Safety-critical — turn off, read this.

7 signs repair isn't worth it anymore.