Boiler indicates high system pressure, may discharge water from safety valve and shut down

Safety: Hot water may discharge from the safety valve. Keep clear of discharge pipe outlets.

• Check pressure gauge: If pressure is above 2.5–3.0 bar when hot, the system is over-pressurised.
• Drain excess water: Bleed water from a radiator or drain point until the cold pressure returns to around 1.0–1.5 bar.
• Check filling loop: Ensure both valves on the filling loop are fully closed and that the hose is removed if required by local regulations.
• Expansion vessel: If pressure rises sharply from cold to hot, the expansion vessel may have lost its air charge. A technician should check and recharge or replace it.