CT and VT valves are very important as in larger heating systems as they are the method of providing the right temperature hot water from boiler(s) to the various equipment that needs it, such as hot water cylinders and heating circuits.
CT and VT valves form a valve body and an Actuator head that is fitted to the valve body to replace the lever. HeatingSave is used to control the Actuator. If a problem occurs, a slipper valve is installed on the boiler flow, which is placed just after the central heating pump. If you open the valve it will cause some of the flow into the heating circuit whilst the rest returns to the boiler, this is called a "bypass".
The HeatingSave low-cost building management system (BMS) also controls 3-port valves. This is particularly useful as it regulates the heating system's functionality and reduces energy costs.