Frequently asked questions, tips & advice for installing an UFH System

What is the difference between Invisible Heat pipe and the various other pipes available?

For starters make sure your pipe has an oxy diffusion barrier & always check your guarantee.
Invisible Heat Standard Pipe : Type - IH - PE - RT 80 - This is five layered pipe with an EVOH oxygen diffusion layer in the centre, this means that the diffusion layer cannot be scratched or damaged during installation. The EVOH barrier exceeds the DIN 4726 standard by ten times. The pipe has a 16mm OD with a 2mm wall thickness. This pipe can be compared favorably to any of the other pex pipes being used, however due to our manufacturing process IH - PE- RT pipe, is more flexible and has more elasticity compared to similar pipes.

Invisible Heat Heavy Duty Pipe: Type IH - PE- RT 80 - This has the same construction as the standard pipe, however is 2 x times heavier than the standard pipe. It has a 20mm OD and a wall thickness of 3.4mm with a stretch capacity of 400 % - the most durable UFH pipe on the UK market today.
This pipe is recommended in commercial work or when installed within the structural slab, also can be used in landing strips, Flyovers & Driveway heating.
A Normal floor heating system runs @ 1.5 Bar with a water temperature of 55C - the expected life span of the pipe will therefore be in excess of 150 years.

TEST Results of the PR - RT pipe from SKZ, KIWA/KOMO
Life span
1.2 Years
50 Years
100 Years

What is the difference between our manifolds and our competitors?

All manifolds are custom built, they are made of 4mm steel, your typical boiler is only 3mm thick.

Type - Invisible Heat Compact Manifold - Designed especially for the self Installer.

A self regulating manifold with unrivalled response times- it comes complete with integrated pump and mixing valve, pre assembled, ready to fit, simply connect up the UFH pipes, connect a flow & return to the boiler, fit the regulating valve and the system can run. We will be introducing a stainless steel version of this popular manifold in the near future.

Type - Invisible Heat Low Temperature  manifold - The IH LT manifold is equivalent to any of the competitors units - a simple flow & return unit - available from 2-20 groups/zones
You still need to add a pump, mixing valve and of course the labour cost to fix these parts, you also have a cupboard full of dated plumbing work, once you add these costs up you can see why the Self regulating manifold is so popular, this simply due to its competitive price, easy to fit and more importantly ease of regulation.

What are your Guarantees?

IMPORTANT: Always ensure you have a pipe with an oxygen diffusion barrier - All IH pipes have this.
Both IH - Standard & HD pipes have a 50 year guarantee, check out You have a written Insurance backed guarantee for the first Ten years. A Calculation & Design guarantee - No time limit - Important - most UK companies do not have this: - ask for a valid written copy.

Suitable Floor Finishes for Floor Heating

Remember all new houses have moisture - get the heating running, it's good for the entire fabric of the building.

To ensure & achieve optimal heat output and temperatures, you require good contact between the floor structure and floor covering with no air gaps.

Generally speaking, thick cork & soft woods are not suitable for floor heating, watch out for some of the new laminate boards and their means of fixing to the floor and the underlay they use, if this is too thick, this should not exceed 2mm & it will insulate your floor.

1. All stone, Concrete, screeds, natural stone, Ceramic & quarry tiles, slate, allow excellent heat transfer & heat output.

2. Linoleum and vinyl- not thicker than 5mm
Important : ensure when gluing Lino/Amtigo to the concrete or screed, that the concrete or screed is dry and all moisture is out - get the heating running to dry out the floor, failing to do this, could cause condensation on the underside of the flooring.
3. Carpets - All carpets are suitable, however, the total carpet thickness should not exceed 12mm. If the carpet has a foam backing it must not be more than 3mm. Underlay is not necessary, the function of Underlay is to prevent wear & tear on the underside of the carpet, however usually a thinner, cheaper type is used - approx 3mm with no air pockets.
The carpet can be laid loose, tensioned or glued to the floor.
4. Chipboard, Ply, Wood, Laminate flooring - good contact with the floor is essential, avoiding air gaps, membranes for laminate flooring, must not be thicker than 2mm with no air pockets, start up the heating to dry out the concrete or screed - ensure the concrete or screed is dry, with all moisture out prior to applying any wood finish -

5. Hardwood flooring - wood should have a moisture content of not higher than 10%.
The total wood thickness should not exceed 22mm, ensure the concrete or biscuit is dry and all moisture is eliminated, prior to applying ANY wood finish - start up the heating to dry out the concrete or screed
Partition Walls
When partition walls are to be placed after the heating pipes are installed, special building adhesives are recommended thus preventing any damage to the floor heating pipes, these adhesives are proven to be stronger than nailing, example are "No Nails" and "Bonded" which you can get from your builders merchants.

Accidents & Damage to the pipes.

During installation or when the pipes are exposed, the pipes are vulnerable, also when installing wooden floors - accidents happen - don' t worry, special pipe connectors are available.

What type of boiler can I use?

The short answer is - any boiler or heat source, that can produce heat from 40-90C.
We can advise you, but firstly what do YOU prefer? Oil or gas fired, Combi or a System Boiler with Hot water cylinder, a Condensing Boiler, Aga's, Rayburns, back boilers, wood chip burners, heat pumps, solar, District source.


Is every room controllable?

All main rooms have a room stat or sensor, which controls the thermo actuator on the manifold. This allows hot water to the desired room and also switches on the pump and boiler as required.

Do I need an outside compensator ?

No - as the floor heating temperature is already down to 50C, the gain of dropping the temperature any further are very small. For example a drop from 40 -50C will make the system run @ 57% of its capacity.
The standard response time of 2 -3 hours will become 7-9 hours therefore we do not recommend Outside compensators for Private Domestic use.
However in Large commercial premises or renovation projects e.g. Churches, the pipes may be laying fairly deep underneath the floor therefore not giving any response time, in these situations the system will run 24 hours a day - 365 days a year & the outside compensator will slowly raise the temperature & reduce them according to the season.