Manifold :
A manifold is typically used with water-based underfloor heating systems. It is a central component that controls the circulation of heating water across different underfloor heating circuits. The manifold consists of a supply and a return rail, each equipped with valves and flow meters.
To identify whether your system uses a manifold, look for a central distribution box — usually installed near the boiler or heat pump. This box should contain multiple valves and flow meters and be connected to the underfloor heating pipes.
Example image: Manifold (close-up view)
RTL Valve (Return Temperature Limiter):
To check whether your system uses an RTL valve, look for a valve installed directly on the underfloor heating pipes, typically at the point where the heating circuit enters the room. The RTL valve frequently has a temperature scale on it.
It is often used in smaller, retrofitted areas (e.g. single rooms like bathrooms) and does not require a full manifold system.
Example image: RTL valve