Cox Geelen


We rely on our central heating system every day, whether for hot water or heating, it is hard to imagine life without it.

Obviously, a boiler needs regular maintenance until it needs to be replaced. It is important to know that replacing the boiler alone is not enough; the flue system must also be checked and usually replaced. 

Whether a central heating appliance needs replacing depends on various factors. The appliance may be defective or outdated. It is no longer possible to purchase old fashioned central heating boilers, as these no longer comply with European energy regulations. If the boiler is part of a collective flue gas system, in some cases, it may be necessary to replace all appliances at the same time.

It is important to note that it is not enough to replace the boiler alone; the flue gas system must also be checked and usually be replaced. The flue gas exhaust of an old fashioned boiler can reach a maximum temperature of up to 160° C. For this reason, the flue gas systems were made of galvanised steel, aluminium or stainless steel.

When the old appliance is replaced by a modern condensing 'high efficiency' boiler, the flue gas system must always be renovated as well. The water vapour produced by combustion not only condenses in the boiler, but also ends up in the flue gas outlet. The resulting condensate has a high acidity level. An aluminium flue pipe could become seriously corroded, causing leakage, and is therefore unsuitable.

Flue gas systems dwellings   Flue gas systems for multi-storey residential buildings


Cox Geelen's flue gas exhaust systems meet the highest quality standards.


Plastic flue systems

Condensing boilers emit flue gas at a much lower temperature. Therefore, when renovating the old flue system in a single-family dwelling, plastic flue material is often used. The use of plastic PP flue systems has many advantages; it is durable, lightweight and easy to install. In addition, PP is resistant to aggressive condensate, which results in less contamination of the boiler. Cox Geelen developed the CoxHYBRID renovation flue system, a modular PP CFS system, for renovation of a collective shaft.

Cox Geelen develops and manufactures flue gas systems for various heating-related products, such as high-efficiency boilers. We offer a very comprehensive range to meet all demands. Our product range includes all components from boiler connection, such as adapters and boiler connection pieces, to roof and wall terminals.


For renovation of shared chimneys, please contact us for advice without obligation.  Contact


Connecting materials - concentric and single wall

Connecting materials are available in concentric Alu/Alu, PP/Alu, PPs/Alu, Stainless steel/Alu and double-walled insulated Stainless steel versions. Single wall systems are available in UV-resistant PP, fire-retardant PPs, Aluminium and Stainless steel.

Concentric flue gas systems    Single wall flue gas systems


CFS for multi-storey buildings

Cox Geelen also manufactures combined air supply and flue exhaust systems (CFS) for multilayer construction. The CoxHYBRID CFS PP system has been specially developed for CFS renovation, and can also be used for new buildings.

Flue gas systems for multi-storey residential buildings

Delivery program

The completely updated digital Cox Geelen delivery program can be consulted online with our product finder.

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