Underfloor Heating Manifolds

Everything you need to know regarding our wet underfloor heating manifolds and accessories. The central hub to your underfloor heating system.

What is an underfloor heating manifold?

An underfloor heating manifold serves as the heart of a wet underfloor heating system. Managing the distribution of heated water from the heat source to different zones. The underfloor heating manifold provides precise control over each zone by regulating the flow and temperature of water. This control provides savings by enhancing your heating efficiency. A manifold permits uniform and optimal heating conditions across the entire home.

Underfloor heating manifold diagram

Blending Valve
A blending valve regulates the temperature of the water circulating within the UFH system. The temperature of the hot water from the heat source may be high, reaching around 80 °C. The standard temperature in an UFH circuit is 50 °C. The blending valve adds the cooler water returning from the loops to the hot water from the heat source. This adjusts the overall temperature to match the desired set point. This precise temperature control provides optimal performance of the heating system.

Actuators
An actuator connects to the underfloor heating manifold above each of the return ports. Each actuator is responsible for controlling the flow of hot water through the pipes. Coordinating with the wiring centre, each actuator controls a single loop in the system. When the actuator receives a signal, it can open or close adjusting the flow of water through the pipe. Actuators adjust the flow of water, ensuring precise temperature control in each loop.

Pump
The pump connects to the UFH manifold and is the main driving force behind the underfloor heating system. The pump’s primary function is to circulate heated water from the heat source through all pipes connected to the system. Using an efficient pump maintains the correct flow rate of water through the UFH system.

Components of an underfloor heating manifold

  1. Flow Meter – Measures the flow rate of water passing through each loop. One is required for each port.
  2. Flow Manifold Rail – The flow rail houses all flow ports and flow meters.
  3. Return Manifold Rail – Holds all return ports and flow caps.
  4. Flow Pipe Connection Port – One end of the pipes connects to these ports. water flows from the underfloor heating manifold into the pipes from here.
  5. Return Pipe Connection Port – The other end of the pipes connects back to these ports. Water passes back into the system from here.
  6. Flow Ball Valve – Provide a shut-off mechanism in the flow
  7. Return Ball Valve – Provides a shut-off mechanism in the return
  8. Flow caps – These change the flow of water within each loop. Swapped with actuators where multi-zone control is a requirement.
  9. Air Vent– Releases trapped air within the system.
  10. Fill Port– Provides port to fill the system with water using a hose.
  11. Pressure Gauge – This allows you to monitor pressure within the manifold.
  12. Drain Port – Provides a port to drain the system using a hose.

Underfloor heating manifold dimensions

Below are the dimensions of our underfloor heating manifold and control pack.
The installer should allow for the following recommended clearances when mounting the manifold on the wall:
200 mm between the finished floor level and the bottom of the manifold. 100 mm above the manifold. 50 mm on either side of the manifold.

Layout 1 is the standard setup for a manifold. Ball valves are placed between the manifold and the pump. This allows servicing or maintenance without draining the entire system.

Port 2 3 4 56 7 8 9 10 11 12
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Layout 2 is preferred when horizontal space is limited. Installing the ball valves below the pump allows the length to be decreased. Shut-off valves are still included in the system.

Port 2 3 4 56 7 8 9 10 11 12
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Included in our underfloor heating manifolds

Our underfloor heating manifolds range between 2 and 12 ports. Complete with adjustable flow meters, fill & drain points, and automatic air vents. Manifold adaptors in sizes 12,15,16 and 17 mm can be added to the order. Ball valves are also available with or without temperature gauges.

Pressure Gauge/ Drain Point
Air Vent/
Fill Point

Key Features

Manifolds

Actuators

Control Pack

Installation of an underfloor heating manifold


This guide outlines key steps for installing an underfloor heating manifold.
Visit our installation blog post for further details.

Position the underfloor heating manifold in the centre of the property. Distribution to each heated area is efficient and involves minimal long pipe runs. Ensure pipework to and from the boiler can reach the designated manifold location. If unsure, our engineers can suggest a manifold location.

The installer should allow for the following recommended clearances.

  • 200 mm between the finished floor level and the bottom of the manifold
  • 100 mm above the manifold
  • 50 mm on either side of the manifold

Your underfloor heating manifold can be assembled in various ways. This is chosen based on the available space at the manifold location. Two assembly layouts can be seen above.

  1. At your chosen manifold location, mount the manifold on the wall using strong fittings. Follow the specified installation clearances.
  2. Insert the Auto Air Vent assembly and pressure gauge assembly. Example show on our blog.
  3. Connect ball valves to the other end of the manifold.
  4. Connect and tighten the manifold control pack (where applicable). Ensure that the pump and blending valve are both in the correct orientation. Denoted by arrow markings on each unit.

Pipes are connected using manifold adaptors. Varying sizes of pipe can be connected to the manifold using adaptors. We supply 12, 15, 16, and 17-mm adaptors which can be included.

Slide the nut over the end of the pipe. Fit the split compression olive to the pipe and insert the push fitting into the end. Ensure the push fitting fits at the end of the pipe before proceeding to connect to the manifold. Attach the assembled pipe end to the related port. Torque the nut to approx. 50 Nm or one-and-a-half spanner turns after hand tightening.

Connecting to the central heating source is an important step in installing an underfloor heating manifold. This must be done correctly to ensure the correct function of the system. If you are unsure we recommend employing a heating engineer.

Please note that VPS will not conduct design works of the hot inlet pipework; a qualified plumber or confident DIYer should conduct this.


Filling the system can be done via the fill and drain valves. The fill vent is connected to a main water supply. To help you we have created an in-depth filling & testing guide.

Testing is required after the system has been installed and filled. You must test the completed system to 6 bars for a minimum of 1. This step is essential and must be completed before any covering is laid.

Troubleshooting underfloor heating manifold FAQs


Below is a quick guide for identifying problems with your underfloor heating manifolds.

  1. Power Supply: The thermostats and wiring centre are the powered components of the system. Ensure both receive power and are working correctly. The pump and actuator are powered through the wiring centre. Ensure there is no interruption in the power supply.
  2. Thermostat: Verify that the thermostats are set to the desired temperature. The thermostats will indicate when they are signalling for heat. Check the related actuator to see if the valve is open.
  3. Valve: Ensure valves are not stuck or blocked. Valves can get jammed due to debris or sediment build-up.
  4. Pressure: Check the pressure flow meters on the manifold. Ensure system pressure in all loops is within the recommended 1 and 2 bars. other measurements could indicate problems in the system.
  5. Balancing: Uneven heating or colder spots in certain areas could indicate imbalances in the system or incorrect zoning settings.
  6. Temperature: Check the temperature difference in the flow and return rails. Indicated on the 2 dials on our standard control pack. The temperature drop should be around 5-10 °C. If the value is out with this range, the circulation pump or flow rates may be the cause.
  7. Call VPS: If you’re uncertain about the problem, give us a call. We will do our best to identify any issues in the system.

Underfloor Heating Manifold FAQ’s

We’ve answered a few common questions regarding underfloor heating manifolds. If you further advice give us a call.

Yes, the manifold is the central hub of the system. Its purpose is to distribute water to each loop in the system.
A small single room is the only instance a manifold wouldn’t be required. This would use a single-zone kit

Underfloor heating manifolds should be placed in an area that is easy to access for any future repairs or upgrades. It is recommended that there is 200 mm between the floor level and the bottom of the manifold. 75 mm clear space at the top. 50 mm on the left and right sides of the underfloor heating manifold.

The size of the manifold relates the the number of loops in the system, indicated by the amount of ports on the manifold. The number of ports used in an underfloor heating system will depend on various factors. Size of the heated area, pipe spacing, number of different zones, and distance between zones and the manifold.

There’s a lot to consider to determine an accurate estimate for the size of manifold. Our design team uses specialised CAD software to estimate. Allow us to provide a free accurate quotation of your project.

Although challenging, installation can be completed by a competent DIY’er. Time must be taken to fully understand the installation process and requirements.

If you are unsure about any step we recommend using a qualified plumber or heating engineer to complete the manifold installation. Connection to the heat source is a difficult task and must be completed by a certified gas-safe engineer. Installation also includes electrical work connecting thermostats and other equipment. This can be a dangerous and difficult task, if inexperienced we recommend hiring a qualified electrician.