RWC Reliance Water Controls Speedfit MVKIT03 Service Kit, Maintenance Kit, Repair Kit, Spares Kit, Replacement Parts Kit

Underfloor heating warms a room from the floor up, using warm water pipes or electric heating elements laid beneath the floor finish. This category covers manifolds, control packs, connectors, system plates, edge insulation, thermostats and wiring centres for water systems, plus electric heating foil kits, insulation boards, membranes and cables.

Water or electric

A water (wet) system circulates warm water from a boiler or heat pump through loops of pipe, often 16mm, laid under the floor. Each loop connects to a manifold, and actuators on the manifold open and close the loops for each zone under the control of room thermostats and a wiring centre. An electric system heats foil, mats or cables directly from the electricity supply, controlled by its own thermostat. Pipes and elements can sit in a screed or on insulation boards and plates; follow the maker's guidance for your floor type.

Insulation and controls

In England, Approved Document L expects insulation under underfloor heating to limit heat lost downwards, with higher levels where the system runs intermittently or sits over an unheated space. Every underfloor heating system should have controls that adjust the operating temperature, and room thermostats for electric systems should have a manual override. New wet heating systems should be designed to run at a flow temperature of 55°C or lower where this is feasible.

Electrical safety

In England, installing a new electrical circuit, or adding to or altering a circuit in a room with a bath or shower, is notifiable under Part P of the Building Regulations. It must be done by a registered competent person or notified to building control. Check that your floor finish is suitable for use over underfloor heating.

For thermostats and timers, see heating controls, or browse pipe systems and fittings.