Underfloor heating manifold diagram

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 manifold can provide precise control over multiple zones by regulating the flow through separate pipes. This control provides savings by enhancing efficiency. A manifold permits uniform and optimal heating conditions across the entire home.

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The manifold plays a crucial role in distributing heated water to the relevant zones. The diagram below displays the relationship between various components in your underfloor heating system. Heated water passes into the system from the heat source, through the blending valve and pump. The heated water flows to the relevant zones which require heat.

Pump
The pump connects to the UFH manifold and is the main driving force behind the 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. Our manifold control pack includes a pump, blending valve, and the correct fixtures to connect straight to the manifold.

Blending Valve
A blending valve regulates the temperature of the water circulating within the UFH system. If using a gas or electric boiler, the flow temperature can reach as high as 80 °C. The standard temperature in an UFH circuit is between 35-50 °C. The blending valve adjusts the flow to the desired temperature. This is done by blending the warm flow from the heat source with the cool water returning from 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.

Components of an underfloor heating manifold

Flow Meter – Measures the flow rate of water passing through each loop. One is required for each port.
Flow Manifold Rail – The flow rail houses all flow ports and flow meters.
Return Manifold Rail – Holds all return ports and flow caps.
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.
Return Pipe Connection Port – The other end of the pipes connects back to these ports. Water passes back into the system from here.
Flow Ball Valve – Provide a shut-off mechanism in the flow
Return Ball Valve – Provides a shut-off mechanism in the return
Air Vent– Releases trapped air within the system.
Fill Port– Provides port to fill the system with water using a hose.
Pressure Gauge – This allows you to monitor pressure within the manifold.
Drain Port – Provides a port to drain the system using a hose.

Underfloor heating manifold dimensions

Below are the dimensions of our manifold and control pack. The installer should allow for the following recommended clearances when mounting on a 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
Layout 2

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	5	6	7	8	9	10	11	12
A	189	239	289	339	389	439	489	539	589	639	689
B	273	323	373	423	473	523	573	623	673	723	773
C	465	515	565	615	665	715	765	815	865	915	965

A – Width of manifold including fill & drain ports
B – Width of manifold & ball valves
C – Width of manifold, ball valves & pump

Underfloor heating manifold dimensions diagram

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	5	6	7	8	9	10	11	12
A	189	239	289	339	389	439	489	539	589	639	689
B	365	415	465	515	565	615	665	715	765	815	865

A – Width of manifold including fill & drain ports
B – Width of manifold & ball valves

Troubleshooting your manifold

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

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.
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.
Valve: Ensure valves are not stuck or blocked. Valves can get jammed due to debris or sediment build-up.
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.
Balancing: Uneven heating or colder spots in certain areas could indicate imbalances in the system or incorrect zoning settings.
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.
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, if you need 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

An underfloor heating manifold should be positioned central to the heated areas. This reduces the length of pipes running to all rooms. A popular position is often in a cupboard below the below a staircase, central to most houses and is easy to access and is often unused.

The chosen area must have a flow and return from the heat source. Placing the manifold near pipework, such as bathrooms, kitchens, or a utility, is often advantageous because these areas already have hot and cold water supplies making it easier to connect the manifold to the heating system.

The chosen position must be 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, and 50 mm on the left and right side.

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 hence our design team uses specialised CAD software to calculate the required materials. 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.

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What is an underfloor heating manifold?