These Honeywell 3-port valves feature 3 ports (1 inlet and 2 outlets) and divert the flow between 2 outlets or mixes. 3-port motorised valves are used to control the temperature of the fluid by either diverting or mixing hot/cold water, and they can ensure the right temperature of water circulates through different parts of the system. These Honeywell heating controls are designed to be durable, optimising your heating controls for more efficient heating. Filtering heating controls by brand can give you peace of mind that you're purchasing from a manufacturer you know and trust.