817-D1011 - 54529

District heating & pre-insulated pipe

What is district heating?

District Heating is the concept of one large energy centre to provide the heat demand for a number of properties, residential, commercial or multi occupancy. The Energy Centre can use a variety of heat sources such as fossil fuels (e.g. gas CHP), Energy from Waste, industrial waste heat or renewable energy sources such as heat pumps, biomass or anaerobic digestion to heat the water.

The hot water travels through an underground insulated pipe network to a heat interface unit (HIU) located in each building, this provides heating and hot water to each building and allows individual temperature control to each building.  The cold water then returns back to the energy centre to be heated and circulated again. 


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Carbon Reductions

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Cost Savings 

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Environmentally Friendly  

Download our guide to pre-insulated pipe and district heating

This guide aims to improve the industry's collective understanding of the heat network itself, addressing some of the most commonly-held misconceptions surrounding them in the process.

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REHAU - Guide - Pre-insulated pipe and district heating-1 - 110424

What we offer our customers

Our service and design support is priority our customers,  our sales, designers and production teams are available to ensure you have the right information to support you through your project. All our key designers are accredited CIBSE heat network consultants and are able to support you with pipe sizing & network routing, diversity and heat loss calculations, operating temperature choice, network optimisation and can provide you with BIM data.

We offer the largest UK stock available with a full cutting service, UK manufacturing and a sales and technical team on hand to assist on-site as well CPD presentations on heat networks. Find out more by taking a look at the videos below.

Our UK sales support

Our technical & design support

Our production

Our UK stock

Product range

817-D997 - 54510

RAUTHERMEX pre-insulated PE-Xa pipe

The efficient solution for heat networks 20 - 160mm

  • Excellent thermal insulation with PU foam and a best in class lambda value of 0.0199W/mK
  • 140mm UNO is the largest polymer flexible district heating pipe on the market which can transport up to 2.5MW of heat at 80°C/50°C flow & return temperatures
  • Largest DUO pipe on the market (75 DUO)
  • RAUTHERMEX Plus available with thicker insulation for up to 20% lower heat losses
  • 10 bar option available
  • No need to compensate for thermal expansion due to bonded foam structure

RAUVITHERM pre-insulated PE-Xa pipe

The flexible solution for heat networks in 25 - 160mm

  • Excellent flexibility and low weight due to corrugated outer jacket and closed cell PEX insulation
  • Long coils up to 330m possible which are 50% longer than similar flexible pipes
  • The only PE-Xa district heating pipe manufactured in the UK which saves an estimated 29% on CO2 emissions annually.
  • RAUVITHERM 125mm UNO can transport up to 1.7MW of heat at 80oC/50oC flow & return temperatures
  • Outer layer of foam is bonded to the outer jacket
Volvo 3 - 55404

818-D119 - 13575

RAUTHERMEX clip shrouds

  • 2nd generation with improved sealing rings allowing up to 20o bending of pipe
  • No hot works
  • Externally tested to 0.3 bar watertightness to EN 489
  • Uses high performance PU foam insulation
818-D184 - 13677

RAUVITHERM heat shrink shrouds

  • Can be used with RAUVITHERM or RAUTHERMEX, or to combine both pipes
  • Externally tested to 0.5 bar watertightness to EN 489
  • Uses high performance PU foam insulation
818-D110 - 13566


  • Two component compression sleeve technology
  • No hot works
  • Over 850 million joints installed worldwide
  • Up to 50% faster connections
  • Full range of tees and terminations
  • Minimal bore reduction
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PP-R district heating pipes

REHAU now offer PP-R district heating pipes in 160-315mm (larger sizes available on request) to allow for a fully polymer heat network.

  • Up to 37% lighter than steel and easier to handle
  • No expansion bends - saving both installation and material costs
  • Up to 19% lower pressure losses than steel
  • Excellent corrosion resistance so no leak detection required
  • Can be combined easily with REHAU's PE-Xa for a fully polymer heat network
  • Over 50 year lifespan at 70oC and 9.5 bar 

What used to be only possible for cold water, gas and steel pipe heating systems is now available for hot water: NEXUS, the first hot tapping system for PE-Xa district heating pipes.

  • Maximum reliability to 110oC due to silicone safety (TUV certified)
  • Up to 80% faster to install than conventional methods *applies for d125, up to 50% at d63
  • Up to 50% cost savings

818-D041_01 - 62156628





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