Manifolds; what they are, and what they do

A key part of any underfloor heating system, a manifold is the link between your heat source – for instance a boiler or heat-pump – and the pipework installed beneath your floor(s).

As well as ensuring that warm water can reach the areas that it needs to, the manifold controls both the temperature and the flow rate of water within the system.

In any underfloor heating installation, each ‘run’ of pipework is commonly known as a ‘circuit’, with each circuit connecting to the manifold. Where multiple circuits are used together, for instance in larger rooms or open-plan areas, they form ‘zones’, which are usually controlled by their own thermostat.

To provide maximum flexibility, Polypipe Manifolds are available in a range of specifications, enabling you to control between 2 and 12 circuits. And because the temperature and flow rate of each circuit is adjustable, you can create the perfect ambient warmth, anywhere in your home.

Stainless Steel Auto-Balancing Manifold

The Components

Your Polypipe Underfloor Heating system can be controlled by either of our highly efficient Polypipe Manifold systems.

The size and type of manifold you opt for is based on the scale of your project, and the budget available. In any case, manifolds are broadly made up of similar core components.

Flow Gauges

Mounted to the flow arm of each circuit, flow gauges are set at the time of commissioning, and ensure the correct flow rate and heat output for their circuits. Each flow gauge features an indicator showing these flow rates, which have to be set manually by the installing engineer when the system is commissioned. However, our stylish Stainless Steel Manifold features Auto-Balancing technology, for faster commissioning and even, consistent flow – at all times.

Drain Valves and Air Vents

Used during the initial filling and draining of a system, drain valves are relatively self-explanatory, and should only be used as part of the initial commissioning and occasional maintenance of the system.

Similarly, air vents, which are installed on the ‘flow’ and ‘return’ arms of the manifold, are used to remove air from the system, similar to bleed valves on traditional radiators.

Control Packs

Converting the flow and temperature of the water provided by your heat source to be suitable for your underfloor heating system, Control Packs are key to ensuring safe, efficient operation.

Featuring pump packs, both unit types circulate the heated water around the system, while their thermostatic valves allow temperatures to be set between 30°C and 60°C, the optimum range for underfloor heating systems.

Control Packs are used for larger areas, up to 140m².

Isolation and Commissioning Valves

Connecting to the manifold arms or mixing unit, isolation valves allow the manifold to be isolated for testing. Commissioning valves, on the other hand, control the flow of individual circuits, for filling, pressure testing and draining.

Actuators

Attaching to the commissioning valves, actuators connect to the wiring centre. Zone thermostats then control the actuators, which open and close each circuit to allow water to flow through the system.

Wiring Centre

Providing the electrical connection between the manifold and its components with the thermostat(s) and heat source, the wiring centre facilitates the operation of the heating system.