What does the Vaillant F.28 fault code mean?

Your boiler is failing to light because it isn't getting enough gas or the spark that starts the flame is not working correctly.

How much does it cost to fix Vaillant error code F.28?

Typical repair cost for the Vaillant F.28 fault is £120-£250 including labour.

Check if your gas meter has credit (if on a prepayment meter)

Either insufficient gas in the system, a defective electrode, ignition lead or electronic ignitor

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.