S.76 — System pressure too low, top up water

What does S.76 mean?

The display shows that the system pressure is too low, indicating that water needs to be added to the boiler. The boiler may not operate until the pressure is corrected.

• Water leakage from the heating system.
• Normal pressure drop over time.
• Recent maintenance or bleeding of radiators.

Click steps to track your progress.

1. 1

   Locate the filling loop, usually a silver braided hose with two valves, beneath your boiler.

2. 2

   Open both valves slowly until the pressure gauge on the boiler indicates it is within the recommended range (typically 1.0 to 1.5 bar).

3. 3

   Close both valves firmly once the correct pressure is achieved. If the pressure drops again quickly, contact a qualified heating engineer.