Schematic diagram of the system 
with a four-way valve
and hot water heater

Four-way mixing valve (cross valve) is used for control of liquid or gas flow. It has four ports - that is four locations for connection of pipes. It is mainly used in the central heating systems for setting temperature of heating water and domestic hot water and to increase the temperature of water returning to the furnace.

It can be used in all types of boilers, mainly for boilers fired with solid fuel with automatic or manual charging and for all heating systems.

Four-way valve lowers operating costs and it connects two functions:

  • it mixes hot water from a heat source (boiler) with cooler water returning from the heating system. The function allows smooth adjustment of the temperature of the heating water with respect to the needs of the heating system. It allows obtaining higher temperature in preheater with respect to water in the heaters. Therefore, it is possible to reduce the temperature in a room without decreasing temperature in the boiler.
  • protects the boiler against low-temperature corrosion, what considerably extends its lifetime. Minimizes difference between outlet temperature of the boiler with respect to return water allowing avoiding dew point and maintaining optimal temperature in the boiler.