2-way and 3-way valve

Choosing a 2-way or 3-way valve

2-way and 3-way valves are used to control water flow in a heating installation. A 2-way valve opens or closes a pipe section, while a 3-way valve can distribute or switch water between different circuits. This makes these valves important for zone control, cylinder control, buffer tanks, mixing systems, heat pumps and central heating installations.

When selecting a valve, connection size, valve type, motor operation, voltage, flow direction, auxiliary switch and application are important. For additional solutions, also view circulation pumps for heating systems, check valves for flow protection and shut-off valves and control valves for service and control.

Important for 2-way and 3-way valves

• Choose between a 2-way valve for opening/closing and a 3-way valve for distribution or switching
• Check connection size, such as 1" female thread, and the technical version
• Pay attention to motor operation, supply voltage, running time and control method
• Check whether an end switch or auxiliary switch is required for the installation
• Pay attention to flow direction, valve position and hydraulic position in the system
• Match the valve to boiler, heat pump, cylinder, buffer tank or zone control

Difference between a 2-way and 3-way valve

A 2-way valve has one inlet and one outlet. This valve is mainly used to open or close a pipe or zone. This makes a 2-way valve suitable for zone control, shutting off a heating circuit or switching a specific group within an installation.

A 3-way valve has three connections and is used to distribute, mix or switch water flow. This is relevant in systems where heat needs to be directed to different circuits, for example towards a cylinder, buffer tank, underfloor heating or radiator circuit.

The correct choice depends on the hydraulic layout of the installation. Always check the system diagram, required function, control method and flow direction before selecting or installing a valve.