/ Blog / Water Underfloor Heating

Manifold for Underfloor Heating Explained

November 17th, 2023 | Water Underfloor Heating

Manifolds are a key part of water underfloor heating systems, being responsible for circulating heated water from your heat source through the connected UFH pipework. In this guide, we’ll explore how a Manifold works to provide comfortable, energy-efficient warmth for your home. You’ll learn more about: 

  • The role of a manifold within a UFH system 
  • The components of the Warmup S3 Manifold 
  • The range of supplementary accessories to use with a manifold 
  • The ease of installation and cost of a manifold  

Understanding how a manifold works with your heating system 

Water underfloor heating systems comprise of pipework installed beneath your floor finish which radiantly warms the room above. The Manifold connects your heat source – a boiler, heat-pump or other – with these water underfloor heating pipes, helping to distribute gently heated water throughout your home whilst managing pressure, flow-rates and temperature regulation. 

Connecting the circuits to the heat source 

Connection to the heat source is made via the primary heating circuit. Underfloor heating pipework can be laid in various patterns forming circuits; a single circuit could be for an individual room or multiple circuits could be used for larger rooms or open areas – these are known as zones. Each floor circuit connects to a centrally located Manifold which allows independent control of the zones. Manifolds can control multiple circuits concurrently, warming different rooms to different temperatures at different times – each zone is typically controlled by a zone-specific thermostat, which is installed within the heated area. 

The heat source supplies water to the Manifold via the Manifold’s optional accompanying Mixing Unit to guarantee designed water temperature (this can be set between 20 – 60 Degrees Celsius). However, if the heat source can constantly provide the necessary water temperature for the system without over-heating, then a Mixing Unit may not be required. Looking to find out more about underfloor heating circuits? Read out expert guide.  

Setting the flow rates 

Manifolds can support up to 120 Metres of underfloor heating pipes per circuit so before the water is delivered into these pipes, the flow rates for individual circuits are set via the Flow Meters to suit the specific circuit’s needs. When correctly configured, this ensures heated zones will evenly heat the space, even where different floor finishes have been used. 


Distributing the heated water 

The optimally heated water, with the correct flow pressure and flow rates, is delivered from the Manifold into the floor via the Manifold’s Flow Arm and after circulating the floor circuits, the water re-enters the Manifold via the Return Arm. The Return Arm features Valves that are often mounted with supplementary Actuators which open and close when instructed by the thermostat (via the Wiring Centre) – thus allowing water flow into the floor circuits and warming up or cooling down the underfloor heating system. 


The components of Warmup’s S3 Manifold 

The Warmup S3 Manifold is ideal for use with all water floor heating systems. It is constructed from a single piece of 304-grade, laser-etched Stainless Steel for high corrosion resistance with no welds that might corrode and leak over time. It is available in a range of sizes for both large-scale and smaller projects and provides control for up to 12 heat zones.  

The S3 Manifold is packed full of innovative features to make your UFH system perform at its best. It uses manual air vents to vent air quickly during commissioning and avoid leaking as they age as well as a Thermomanometer (combined Pressure and Temperature Gauge) on the flow arm, allowing you to check the flow water temperature easily. The Manifold’s Taconova flow meters improve accuracy and reliability for a faster installation. They are set during the installation to configure the correct flow rate for the circuit and to provide the designed heat output for that circuit – which is determined by the floor build-up and heat losses of the area. The S3 Manifold also uses standard 3/4″ Eurocones, making it compatible with a wide range of UFH pipes and fittings and it is supplied with anti-vibration mounts which facilitates an ultra-quiet operation  

The range of supplementary accessories to use with the S3 Manifold 

1. Manifold Mixing Unit

A Mixing Unit is required with the S3 Manifold where the heat-source cannot constantly maintain design temperature. The Mixing Unit blends the heated water from the primary heating circuit with cooler water from within the floor circuits to achieve the ideal design temperature, allowing optimised water temperature regulation of between 20 – 60 Degrees Celsius, the ideal temperature range for water underfloor heating systems. This temperature is configured during the installation process to match the designed heat requirements; which is determined by heat losses, floor construction, heat outputs and other variables.

2. Manifold Isolation Valves

Connected to the S3 Manifold directly, or the Mixing Unit if used, the Isolation Valves allow the manifold to be filled, drained and pressure tested without affecting the primary floor circuits.  

3. Manifold Actuator

The S3 Actuators can be installed with the S3 Manifold to control its circuit valves. Through connection with the Wiring Centre, the floor heating system’s thermostat can control when the Actuators open and close each circuit, allowing the water to circulate through the system. While operational, the Actuator consumes less that 1W of power, making it the most efficient actuator in its class. 

4. In-Wall Manifold Cabinet

The In-Wall Manifold Cabinet has been designed to securely house the Warmup S3 Manifold. It features a classic, stylish design and is available in multiple widths for use with different manifold sizes: 600mm for 2-3 Port Manifolds, 750mm for 4-6 Port Manifolds, 900mm for 7-9 Port Manifolds and 1050mm for 10-12 Port Manifolds. It also offers an adjustable internal depth and height, allowing a truly bespoke installation.  


Installing and controlling your manifold  

Manifold placement is key to ensuring an efficient underfloor heating system. The best location for the manifold is central to the heating zones; by mounting the manifold centrally, pipe lengths will kept to a minimum ensuring the heated water reaches the heated area evenly and efficiently. For larger projects, more than one manifold may be required. If underfloor heating is to be installed across multiple floors, we recommend installing a sperate manifold on each floor.  

Warmup’s S3 Manifold offers a hassle-free installation and using it alongside Warmup’s Wiring Centre and Smart controls offer intuitive heat management for your home. The Wiring Centre controls the electrical aspect of a UFH system and facilitates a connection between the manifold and its components with the heat source and thermostat. When a thermostat calls for heat in a specific heated zone, the Wiring Centre will supply voltage to the relevant Actuator (or multiple, if using more than one circuit per heated zone) which opens the valves and allows warm water to flow through the circuits.  Using a Smart Thermostat to control the system ensures energy-efficient heating with long-term cost-savings on your heating bills. 

Purchasing a manifold with your floor heating system 

Warmup’s S3 Manifold offers expert design at a competitive price. For the simplest two port option without a Mixing Unit, the Manifold retails at £111.95 +VAT, rising in cost with additional ports and components. You can purchase a complete water underfloor heating system with its accompanying manifold using our simple online quoting tool.  


Thinking of installing a new Hydro heating system?

Find out more about installing water underfloor heating systems

Warmup Quoting Tools: instant, accurate, flexible

Warmup offers an extensive range of electric and water floor systems compatible with all floor types, rooms and projects.

Warmup Quoting Tools

instant, accurate, flexible

Quoting Tools: instant, accurate, flexible

Warmup offers an extensive range of electric and water floor systems compatible with all floor types, rooms and projects.

Electric Systems

  • ✓ Ideal for zones less than 25m²
  • ✓ Ideal for single rooms
  • ✓ Does not alter floor levels
  • ✓ Great for renovations

Electric Systems Quote
Thumbnail [200x250]


Water Systems

  • ✓ Ideal for larger zones over 25m²
  • ✓ Rapid auto heat loss calculations
  • ✓ Compatible with existing central heating systems
  • ✓ Great for new-builds

Water Systems Quote & Buy
Thumbnail [200x250]
For areas of 24m2 or more, use our full quoting system
Scroll to Top