BoilerFaultCodesTechnical description
System pressure: Current system pressure
What causes this fault?
This fault occurs when the internal sensor detects that the system pressure has dropped below 0.6 bar or risen above a safe maximum. The most common reason is a slow loss of water through the radiators or a leak, but it can also happen if the filling link was left open after topping the boiler up. When the pressure leaves this safe zone, the boiler's safety software restricts operation to prevent internal damage.
This fault is more common in autumn when homeowners first turn their heating back on after summer, as air can get trapped or seals may have shrunk during the period of inactivity.
DIY fix possible
Locate the internal or external filling link (often a blue lever or braided hose under the boiler).Slowly open the valve(s) until the pressure gauge on the display shows between 1.0 and 1.5 bar.Ensure both valves are closed tightly once the correct pressure is reached.