A recirculation kit is REQUIRED if the water in the system is being recirculated. Temperature control problems will occur if the recirculation kit is not used in a recirculating system. Temperature control problems will occur if a recirculation kit is not installed in a recirculated system. The problem, recirculated water returning to the heater hot, is experienced during times of little or no hot water usage. The movement of the water through the system will cause the blending valve to sense a pressure drop and cause the valve to open and heat the hot water hotter. Eventually, the water in the system will become dangerously hot. Therefore, when recirculating water, it is essential that a recirculation kit be supplied. The recirculation kit allows for the proper mixing of hot and cold water into the system through the use of a balancing valve and a 3-way thermostatic valve. The mixing valve allows for the diverting of hot water away from the heater if the system temperature is already at the heaters set point. For safety purposes the mixing valve is non-adjustable, preventing accidental changes in the hot water system temperature thus preventing any over-temperature situations. See the operation schematic below.

ffh-recirc kit