What does the Vaillant S.40 fault code mean?

Your boiler has detected a minor hiccup and is running in a limited mode to keep you warm while it monitors itself.

How much does it cost to fix Vaillant error code S.40?

Typical repair cost for the Vaillant S.40 fault is £120-250 including labour.

Product is in a temporary test mode or comfort protection mode (detected a temporary fault and continues to run with restricted comfort)

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Break-even maths on monthly cover.

7 signs repair isn't worth it anymore.

Realistic UK prices for a swap.