A floor heating system stands or falls with the right pipes and couplings . Whether you choose a high-quality brand such as Uponor , Rehau , Henco or Robot : make sure that the pipes and couplings are perfectly matched to your distributor and your heating system . Below you will find the most important points of attention and specifications to pay attention to when purchasing.

1. Pipes: material, diameter and application

1. Material

   • PE-RT / PEX (plastic) : widely used and affordable; flexible and resistant to high temperatures.
   • PEX-Al-PEX (multilayer pipe) : with an aluminum core for extra strength, low oxygen permeability and minimal expansion.
   • Henco multilayer pipes (Hencofloor) : a mix of plastic and aluminium for optimum pressure and temperature resistance.
   • Uponor Comfort Pipe / Rehau Rautherm : specially developed pipes with a high diffusion-tight layer, so that oxygen and moisture have almost no chance.

2. Diameter

   • 16 mm is the most common size for underfloor heating; suitable for most homes and small/medium commercial spaces.
   • 20 mm (or larger) can be useful for larger surfaces or specific situations with high heat demand.
   • Pay attention to the recommendations of your distributor : some brands (e.g. Robot, Uponor or Rehau) recommend a specific diameter for optimal flow.

3. Application

   • Wet construction : pipes that are suitable for laying in the screed (concrete, cement). They often have extra robust properties.
   • Dry construction : lighter and more flexible, so you can click them into special plates or profiles.
   • Also check the minimum bend radius, especially in curves or tight corners.

4. Temperature and pressure resistance

   • Most underfloor heating pipes operate up to 6 bar and a maximum temperature of approx. 70-95 °C.
   • Choose pipes that meet the standards of your boiler or heat pump (low temperature vs. conventional system).

2. Couplings: safe and leak-free connections

1. Type of coupling

   • Compression fitting : for copper or multilayer pipes, where a compression ring seals the connection.
   • Press coupling : widely used in professional installations, fast and reliable by 'pressing' with a special tool.
   • Screw coupling : popular for radiator systems and certain underfloor heating manifold connections.

2. Diameter and brand compatibility

   • Please note that the outer diameter of the pipe exactly matches the coupling (e.g. 16 x 2 mm).
   • Some brands (such as Uponor , Rehau , Henco and Robot ) offer brand-specific couplings that fit perfectly with their pipes and manifolds.
   • Universal couplings may work, but check that they are the same size and tolerances.

3. Material and sealing

   • Brass, stainless steel or plastic: each material has its own properties in terms of corrosion resistance and price.
   • Check the seal (O-rings, gaskets) and replace them in time during maintenance to prevent leaks.

4. Assembly and tools

   • For compression fittings you will need a wrench or compression fitting pliers.
   • For press couplings, a press machine with the correct jaw size.
   • Always read the installation manual so that you know exactly how tightly or deeply the tube should be inserted.

3. Cooperation with your distributor

• Flow and diameter
  The correct pipe size and couplings ensure optimum water flow in the manifold. This ensures that each group heats evenly.
• Minimize pressure loss
  Well-chosen couplings and pipes with the right diameter reduce the risk of unnecessary pressure drops. Your pump then has to work less hard, which saves energy.
• Compatibility
  Many brands, such as Robot or Rehau , design their couplings and tubes specifically to work best with their own distributors. If you use multiple brands together, check the specifications extra carefully (e.g. 16 x 2 mm, 17 x 2 mm, etc.).

4. What else do you pay attention to?

1. Insulation and fastening
   • Choose good quality insulation boards, tacker boards or stud plates so that your pipes are mounted safely and efficiently.
2. Dirt separation
   • A dirt separator (e.g. Spirotech) prevents dirt or air from attacking the couplings and pipes, which extends their service life.
3. Maintenance and lifespan
   • It is advisable to regularly check for leaks or wear, especially on the couplings.
   • Many multilayer pipes have a lifespan of 50+ years when used correctly.

Need advice?

With the wide range of pipes and couplings at viawww.nl you can optimally connect every underfloor heating manifold. Whether you choose Uponor , Rehau , Henco or Robot : we are happy to help you find the right combination. Do you have questions about diameters, materials or installation? Please feel free to contact us — our experts are ready to make your underfloor heating project a success!