Boiler frequently loses pressure and needs topping up every few days or less.

Safety: Do not overfill the system above the recommended pressure.

• Inspect for visible leaks: Check all radiators, valves, and joints for signs of water or staining.
• Check PRV discharge: Look at the outside discharge pipe while the boiler is running; dripping indicates a passing pressure relief valve.
• Monitor pressure cold vs hot: If pressure rises sharply when hot then drops to zero when cool, the expansion vessel is likely faulty.
• Technician – expansion vessel: Isolate and drain the system, then check and recharge or replace the Beretta expansion vessel.
• Leak detection: A heating engineer may need to use leak detection methods for hidden pipework.