Display indicates low water pressure or water pressure fault (for boiler/furnace with water circuit)

Safety: Allow the system to cool before adding water. Overfilling can cause relief valve discharge.

Steps:

• Check pressure gauge: Read the system pressure on the gauge. Typical cold pressure is around 1.0–1.5 bar (check your manual).
• Top up system: If pressure is low, slowly open the filling valve and add water until the correct pressure is reached. Close the valve securely.
• Bleed air: Bleed radiators or air vents to remove trapped air, then recheck pressure.
• Inspect for leaks: Look for visible water leaks around the furnace, piping, and radiators.

If pressure drops repeatedly, a technician should check the expansion vessel, pressure sensor, and system for hidden leaks.