What does the Saunier Duval 0 then 8 fault code mean?

Your boiler has shut down because a waste water pipe is blocked, preventing it from safely draining away the liquid produced during normal operation.

How much does it cost to fix Saunier Duval error code 0 then 8?

Typical repair cost for the Saunier Duval 0 then 8 fault is £90-180 including labour.

As a safety feature the boiler will stop working if the condensate drain becomes blocked. (May be due to ice in freezing conditions).

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

Safety-critical — turn off, read this.

Winter cause of ignition lockouts.

7 signs repair isn't worth it anymore.