Safety relief valve

Selecting a pressure relief valve

A pressure relief valve protects a heating system, heat pump, boiler installation or buffer tank against excessive system pressure. When the pressure rises above the set opening pressure, the valve opens automatically and discharges water in a controlled way. This helps prevent unnecessary stress on pipework, heat exchangers, fittings and other installation components.

For correct selection, the valve must match the application, maximum operating pressure, connection size and installation position. In a complete heating installation, a pressure relief valve is often combined with expansion vessels for pressure absorption, boiler safety groups for heating systems and filling hoses for controlled system filling.

Important when choosing a pressure relief valve

• Always check the correct opening pressure for the installation
• Match the connection size to the pipework and safety group
• Check the temperature rating and suitability for heating water
• Install the valve in a technically correct and accessible position
• Provide a safe discharge route when the valve opens due to overpressure
• Check compatibility with the boiler, heat pump, water heater or buffer tank
• Have installation and replacement carried out by a qualified installer

Pressure protection for heating systems and heat pumps

In hydronic heating systems, pressure can rise due to temperature increase, water expansion or incorrect system filling. A correctly selected pressure relief valve prevents the pressure from rising too far and contributes to safe system operation. This is important for traditional heating systems as well as heat pumps, buffer tanks, water heaters, underfloor heating and combined installations.

Besides pressure protection, water quality and air removal also influence system reliability. Where required, combine correct pressure control with dirt separators for system protection and air separators and air vents for heating systems. This helps reduce dirt particles, air accumulation and unnecessary strain on components.

During renovation, service or replacement, always check whether the new pressure relief valve matches the existing installation. Key points include system pressure, position near the heat generator, connection to the pipework and compatibility with the other safety components.