Boiler displays low water pressure alarm, heating and hot water disabled

Safety first: Allow the system to cool before topping up. Hot water can cause scalding if a leak opens.

• Check pressure gauge: Confirm the displayed pressure is below the recommended level (often under 0.8 bar). The boiler will lock out to protect itself.
• Top up via filling loop: Locate the filling loop (flexible hose or built-in valve set). Slowly open the valves until the pressure rises to about 1.2–1.5 bar, then close both valves firmly.
• Inspect for visible leaks: Walk around radiators, valves, and visible pipework. Look for damp patches, green/white staining, or drips. Tighten any accessible compression joints gently; do not overtighten.
• Monitor pressure: Over the next 24–48 hours, check if the pressure drops again. Repeated loss of pressure suggests a hidden leak or failed expansion vessel.
• Call a technician if recurring: A Nibe technician can test the expansion vessel pre-charge, replace the vessel if the diaphragm has failed, and locate concealed leaks.