UFH manifold sizes and dimensions: how much space you need

Manifold dimensions matter twice: once when you pick the port count, and again when you pick the wall, cupboard or cabinet it has to fit. A 12-port assembly with a pump set on the end is a very different object from the 4-port manifold in the brochure photo, and the pipework needs more room than the manifold itself.

This guide gives published widths by port count, the clearances makers ask for, the standard connection sizes, and the pressure and temperature ratings, so you can plan the space before anything is ordered. For choosing the port count itself, see how many manifold ports do I need.

How wide is a UFH manifold?

Roughly 50mm per port plus the end fittings, because the loop outlets sit at 50mm centres, which is the spacing on the MaxHeatUFH auto-balancing manifold. Published widths differ between makers mainly because of what is included at the ends. One manufacturer lists its manifold bars without attachments; another lists its assembled stainless steel manifold:

Ports	Maker A, bars only	Maker B, assembled
2	126mm	280mm
4	226mm	380mm
6	326mm	480mm
8	426mm	580mm
10	526mm	680mm
12	626mm	780mm

Both tables step 50mm per port. The difference between the columns, roughly 150mm, is what end caps, air vents, fill valves and isolating valves add, so when you plan a space, work from an assembled figure, not a bare-bar one.

For height and depth, one manufacturer quotes 320mm tall and 71mm deep for its assembled manifold. Actuators, flow meters and valve handles stand proud of that, which is why manifold cabinets are deeper than the bare figure; our guide to manifold cabinets and boxing in covers cabinet sizes.

How much clear space does a manifold need around it?

One manufacturer's installation instructions ask for a minimum of 300mm from the finished floor to the lowest part of the system, including the pump set if fitted, and 100mm above and on each side for future maintenance.

The 300mm below is not spare air. Every loop rises out of the floor and has to bend up into its port without kinking, and 16mm pipe cannot be bent tightly. With 10 or 12 loops arriving, the space under the manifold fills with pipe quickly. The 100mm either side is what lets you swap an air vent, a flow meter or the pump later without taking the manifold off the wall.

Mounting height is also worth planning: with 300mm below the lowest part and the pump set hanging under the bars, the manifold itself usually ends up with its centre around waist height, which makes the flow meters readable at eye level when crouching. Pick the wall using our guide to where to put a UFH manifold, and remember the wall carries the manifold full of water plus the pump, so a stud wall needs a solid backboard.

What are the standard manifold connection sizes?

Most UK manifolds share the same fittings, which is why pumps, valves and actuators interchange so readily.

Connection	Size	Notes
Main flow and return	1in	MaxHeatUFH 1in; other makers 1in or G1in female
Loop outlets	3/4in Eurocone	Takes a connector core sized to the pipe
Actuator thread	M30 x 1.5	On the return bar valves
Flow meters	G1/2in on one maker's manifold	Scales 0 to 4, 0 to 5 or 0 to 6 L/min by maker

Each loop needs two Eurocone connector cores, one for the flow and one for the return, matched to the pipe size; cores are listed for pipe from 10mm to 20mm. Ball valves on the 1in mains isolate the manifold, and the primary pipework from the heat source connects to them. How it all goes together is in connecting a UFH manifold.

How much length does the pump and mixing set add?

Enough that it should be in the plan from day one. The blending valve and pump bolt onto the manifold ends, extending the assembly sideways and downwards, and on a boiler-fed system running hotter than the floor you will almost always have one.

If the full assembly will not fit along one wall, a 90° elbow connector set turns the pump and mixing unit through a right angle, so the manifold sits on one wall of a cupboard and the pump set on the next, with no extra pipework. A 1-port manifold extension is the other space tool: it adds a single loop to an existing Dualmix manifold later, without swapping to a wider manifold.

What pressure and temperature are manifolds rated to?

Ratings vary by maker, so check the one you are fitting:

Manifold	Max pressure	Max temperature
MaxHeatUFH auto-balancing	6 bar	70°C
Maker B stainless steel	5 bar operating (10 bar test at 20°C)	Rated at 80°C
Maker A	8 bar	100°C

All are comfortably above the roughly 1 to 2 bar a sealed domestic system runs at, and above UFH water temperatures, which a blending valve holds between 20 and 55°C on our packs. The test figures matter during commissioning: pressure testing is done against the maker's stated test conditions, not the everyday rating.

Which sizes does MaxHeatUFH stock?

Both of our stainless steel manifolds come in every size from 2 to 12 ports, with 3/4in Eurocone outlets and 1in connections:

• Dualmix stainless steel manifold, supplied assembled with pressure gauge and automatic air vent.
• Auto-balancing stainless steel manifold, with dynamic valves that hold each loop at its preset flow and 0 to 4 L/min flow meters.

Port count is one port per loop, and each 16mm loop is kept to about 100m; see our guide to loop lengths and loops per room. If you are between sizes, the bigger manifold plus blanking caps is easier to live with than a full manifold with no spare port.

Frequently asked questions

How wide is a 12-port underfloor heating manifold?

About 626mm for the bare bars in one manufacturer's published data and 780mm assembled in another manufacturer's, before the pump and mixing set. Allow a metre or more of wall for the full assembly with working space.

How much space do I need under the manifold?

One manufacturer asks for at least 300mm from the finished floor to the lowest part, including the pump set. The loop pipes need that room to rise and bend into the ports without kinking.

How deep is a UFH manifold off the wall?

One manufacturer quotes 71mm for the assembled manifold body, but actuators, flow meters and valve handles stand further out, so recessed cabinets and boxing-in need more depth than the bare figure.

Are manifold connections a standard size?

Largely yes: 1in main connections, 3/4in Eurocone loop outlets and M30 x 1.5 actuator threads are the common pattern, with the Eurocone core chosen to match your pipe size.

Can I make a manifold bigger later?

On the Dualmix, yes: a 1-port extension adds one loop. Needing several more loops usually means a wider manifold or a second one; our guide to manifold ports covers when to split.

Do all ports have to be used?

No. Unused ports are closed with blanking caps and give you spare capacity for a future loop, which is cheaper than changing the manifold later.

What temperature does a manifold run at?

UFH water is blended to between 20 and 55°C at the mixing valve, well inside the manifold ratings in the table above. The limits matter for the primary side and for pressure testing, not normal running.