Boiler frequently loses pressure and needs topping up every few days

Safety: Do not over-pressurise the system. Repeated topping up introduces oxygen and accelerates corrosion.

• Check for visible leaks: Inspect all radiators, valves, and accessible pipes for signs of water or staining.
• Observe safety valve discharge: Look at the safety valve outlet pipe outside; if it drips when the boiler heats up, the valve or expansion vessel may be faulty.
• Record pressure changes: Note cold and hot pressures to provide information to your engineer.
• Technician tasks: A professional will test and recharge or replace the expansion vessel, replace a passing safety valve, and pressure-test the system for hidden leaks.