Polypropylene plastic flue systems are an innovation in the UK so most people don't understand their significant benefits over more traditional metal flue systems when used on condensing boilers, according to Richard Hiblen.
Already used in mainland Europe as the preferred option on most condensing boilers, plastic headers in modular boiler configurations are now starting to be adopted by UK manufacturers.

Our experience of flues over the last 30 years has led us to the conclusion that some metal systems are simply not able adequately to contain the pressure and condensate which modern condensing boilers produce. The number of sites reporting symptoms such as those shown in the photo is on the increase. Plastic flue system can alleviate these problems.

Let's give you a quick run through of the benefits using plastic flue offer over the traditional metal alternatives. As plastic can withstand 25 times the pressure of standard flue systems, you can use the boiler's fan to drive the flue gases through a smaller diameter system, even in multiple boiler cascade systems, through the use of the patented non-return valve at the boiler outlet. This reduces cost and the space used within the building, sometimes even enabling you to use a more direct route for the flue to exit the building.

Furthermore, the typical off-the-shelf range of components in plastic easily matches metal; there is no need for special adjustable lengths because any pipe can be cut to length without affecting performance of the system.

Installers who have already tried and tested the product list this as a major advantage when on site.

Bends are in non-segmented smooth angles which reduce drag and prevents potential leakage and translucent plastic material means you can instantly check that all seals are located correctly.

The fittings automatically ensure the system has the required fall to lead the condensates back to the incorporated drain connection points complete with siphon.

Tested and approved for use on flue gas temperatures up to 120 deg C, inert plastic will not suffer from chemical reaction with the condensates and will, therefore provide your client with a longer lasting system. Recent studies indicate that savings of more than 50 per cent can be made over metal system material costs when plastic is specified and further savings can be achieved because of the speed and ease of installation.

• Richard Hiblen is national sales manager of Specflue