How much does it cost to fix Remeha error code b30?

Typical repair cost for the Remeha b30 fault is £150-300 including labour.

b30 High

Remeha b30 Fault Code

Q: What does the Remeha b30 fault code mean?

Your boiler has detected that the water flowing out to your radiators is significantly hotter than the water returning, suggesting a circulation issue within your heating system.

Also written as B30 — same fault.

The Remeha b30 fault code means: your boiler has detected that the water flowing out to your radiators is significantly hotter than the water returning, suggesting a circulation issue within your heating system.. It appears on 2 Remeha models in our database.

Technical description: Difference between flow and return sensor > VT (parameter)

Typical repair cost £150-300 (including labour)

Engineer required

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

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Remeha models that show the b30 fault code

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

Source

Remeha b30 fault code information on this page is sourced and cross-checked against the official Remeha service / installation manuals for each affected model.

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