How much does it cost to fix Biasi error code E00---684?

Typical repair cost for the Biasi E00---684 fault is £120-£280 including labour.

E00---684 High

Biasi E00---684 Fault Code

Q: What does the Biasi E00---684 fault code mean?

Your boiler has detected that water isn't moving through the system properly, which has caused it to shut down to prevent overheating.

Also written as E00684 — same fault.

The Biasi E00---684 fault code means: your boiler has detected that water isn't moving through the system properly, which has caused it to shut down to prevent overheating.. It appears on 1 Biasi model in our database.

Technical description: Primary circuit flow switch

Typical repair cost £120-£280 (including labour)

Engineer required

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

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Biasi models that show the E00---684 fault code

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

Riva Compact 24S Repair: £120-£280

Source

Biasi E00---684 fault code information on this page is sourced and cross-checked against the official Biasi service / installation manuals for each affected model.

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