How much does it cost to fix Saunier Duval error code 0.5bar?

Typical repair cost for the Saunier Duval 0.5bar fault is £0 - £120 including labour.

0.5bar High

Saunier Duval 0.5bar Fault Code

Q: What does the Saunier Duval 0.5bar fault code mean?

Your boiler has lost pressure, which means there isn't enough water inside the system to circulate heat throughout your home.

Q: Can I fix Saunier Duval fault code 0.5bar myself?

Locate the filling loop, which is usually a flexible silver hose with one or two valves underneath your boiler.

Also written as 05BAR — same fault.

The Saunier Duval 0.5bar fault code means: your boiler has lost pressure, which means there isn't enough water inside the system to circulate heat throughout your home.. It appears on 4 Saunier Duval models in our database.

Technical description: Lack of water fault (<0.5b)

Typical repair cost £0 - £120 (including labour)

DIY fix possible

Locate the filling loop, which is usually a flexible silver hose with one or two valves underneath your boiler.Open the valves slowly to allow mains water into the system while watching the pressure gauge on the front of your boiler.Close the valves firmly once the needle on the gauge reaches between 1.0 and 1.5 bar.

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Saunier Duval models that show the 0.5bar fault code

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

Source

Saunier Duval 0.5bar 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