Standard Control Underfloor Heating

This schematic shows a standard control underfloor heating system with branches off to additional manifolds, and to separate circuits for radiators or towel rails, and domestic hot water.

The primary flow from the boiler is circulated to the underfloor heating manifold where it passes through a thermostatic mixing valve attached to the manifold. The incoming hot water is mixed with some of the returning water from the floor, and the temperature is regulated by a sensing element and the action of the thermostatic valve. The water temperature must be adjusted manually to take account of seasonal temperature variations. A manifold pump circulates water through the underfloor heating pipes. Flow to each circuit is controlled via room thermostats and actuators, which open or close the individual circuits at the manifold.