Boiler frequently loses pressure and needs topping up

Safety: Do not repeatedly overfill the system; this can damage components.

• Inspect visible pipework: Look for damp patches under radiators, valves, and around the Herz boiler.
• Check safety valve discharge: Inspect the safety valve outlet pipe outside; if it is wet, the valve may be passing and needs replacement.
• Test expansion vessel: With system drained, check and recharge the Herz expansion vessel as per the manual.
• Leak detection: If no obvious leaks are found, a heating engineer may need to perform pressure testing or add leak detection dye.