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 £80-150 including labour.

0 then 8 High

Saunier Duval 0 then 8 Fault Code

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

Your boiler has detected that waste water cannot drain away properly, likely due to a blockage or frozen external pipe, causing it to shut down for safety.

Also written as 0THEN8 — same fault.

The Saunier Duval 0 then 8 fault code means: your boiler has detected that waste water cannot drain away properly, likely due to a blockage or frozen external pipe, causing it to shut down for safety.. It appears on 2 Saunier Duval models in our database.

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

Typical repair cost £80-150 (including labour)

DIY fix possible

Locate the plastic pipe exiting your property wall specifically for the boiler condensation.If it is freezing outside, carefully pour warm (not boiling) water over the pipe to thaw any potential ice blockages.Once the pipe is clear, reset your boiler to see if the fault code clears.

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Saunier Duval models that show the 0 then 8 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Saunier Duval 0 then 8 fault code information on this page is sourced and cross-checked against the official Saunier Duval service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026