Load Unit designed to maintain boiler (hydronic fireplace) incoming temperature through a thermostatic valve. It prevents low-temperature corrosion and boiler fouling. Consists of a Grundfos UPM3 25-75 pump, thermometer, TSV5 valve and insulation. The TSV5 valve features no automatic bypass closing, so a balancing valve shall be fitted on the B inlet. Available options with 65 or 72°C opening temperature. For boilers up to 50 kW.