Health & Safety



InnoFlue® is proud to be listed to be both CE EN-14471 and ULC-S636 Class II C. InnoFlue® is certified for sustained operating temperatures up to 230°F (110°C) in North America and 248°F (120°C) in Europe.

People commonly ask if today’s condensing appliances require venting that can handle flue gas temperatures over 200°F (93.3°C). The answer is a resounding – yes. While condensing hydronic appliances (tanked water heaters, tankless water heaters and boilers) are designed to operate at maximum efficiency with a supply water temperature under 150°F (65.5°C) and a return water temperature under 130°F (54.3°C), there are many instances where the flue gas temperature exceeds 149°F (65°C) and even 194°F (90°C). These include commercial hot water applications and instances where homeowners demand quicker reset times. In both these instances, the supply water temperature can be set at 180°F (82.2°C). In condensing appliances flue gas temperatures follow the return water temperature and are typically within 13°F (7°C).

As an appliance ages, scaling develops within the heat exchanger. Without regular maintenance, this can drastically impact efficiency causing large increases to the flue gas temperature. Flue temperatures on appliances in service over one year commonly exceed 200°F (93.3°C). The B.C. Safety Authority conducted a study on in-service heating appliances. The data from the study resulted in a directive that requires the use of Class B or better venting material for all condensing hydronic appliances.


Since its introduction to the European market, InnoFlue® has been designed and used as a combustion gas vent system. That is why, unlike competing polymeric technologies, Centrotherm provides vent system sizing guidelines as well as OEM support for the design and testing of cascade (common) vent systems. This is all in addition to having intuitive parts such as test ports, condensate drains, and siphons that allow the installer time to get optimum performance out the appliance.


PVC and CPVC products are designed for DWV applications. Leading manufacturers, such as Charlotte Pipe, do not certify PVC and CPVC for venting applications. Charlotte Pipe states in their June 9, 2011 Technical Manual, “This standard specification does not include requirements for pipe and fittings intended to be used to vent combustion gases.” Use of PVC and CPVC manufactured by Charlotte Pipe, and other suppliers, places the burden of warranty, performance and support on to the heating appliance original equipment manufacturer, the distributor and the installer.


InnoFlue® is made from environmentally friendly polypropylene. Over 479 million pounds of post consumer non-bottle rigid plastic was recycled in 2009. This is a 47% increase over 2007. 128,582,651 pounds or 27% of this was polypropylene. PVC made up only 6,704,337 pounds or 1% of the recycled total.  Compare this to the over 14 billion pounds of PVC that are produced in North America.

Why is there a difference between the recycle rates of polypropylene and PVC? Polypropylene is manufactured from polypropylene monomer gas, a waste product from the petroleum industry. Polypropylene is a neutral plastic comprised of carbon and hydrogen. Its relatively neutral state, and its ability to be manufactured into goods without additional additives, makes it easier to re-process into new products.

PVC or poly vinyl chloride is comprised of vinyl chloride monomer (VCM) and ethylene dichloride (EDC). VCM is a carcinogen and EDC is a neurotoxin. The manufacturer of these raw materials requires substantial amounts of chlorine and energy. When the entire material supply chain is analyzed, a ton of PVC requires as much as eight tons of oil. Localities surrounding manufacturing facilities of VCM and EDC have higher instances of cancer and other illnesses.

PVC is relatively brittle and difficult to mold without the addition of numerous additives. To counter this, phthalates are added to PVC to soften it. DEHP is the most common phthalate used and is linked to damage to the reproductive system including infertility and testicular damage. As phthalates are not chemically bonded to PVC, they continue to leach out from the product over its life cycle.

PVC releases dioxins, a known carcinogen, when burned. This poses a significant health risk for communities neighboring incinerators and for fire fighters responding to building fires.