What does the Main 20 fault code mean?

Your boiler has lost the chemical signal needed to release gas, so it has safely shut itself down to prevent any unsafe operation.

How much does it cost to fix Main error code 20?

Typical repair cost for the Main 20 fault is £150-250 including labour.

Gas valve connection fault

This is a high 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.

7 signs repair isn't worth it anymore.

Break-even maths on monthly cover.