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  • Installing ThermoPEX piping is easy
  • ThermoPEX 25mm is easier to transport


Choosing the best insulated piping system for your outdoor furnace is imperative to lower heat loss and reduce the amount of wood you'll burn. The ThermoPEX insulated piping system is a proven system that saves energy and maximizes the efficiency of your outdoor furnace.

ThermoPEX is available with two 1-inch* oxygen barrier Central PEX® lines, two 1-1/4"** oxygen barrier PEX lines, or two 25 mm*** oxygen barrier PEX lines (a supply and a return). All ThermoPEX is insulated with high-density urethane insulation and a thick, durable, waterproof polyethylene outer jacket.

ThermoPEX insulated piping saves energy and maximizes efficiency by keeping heat loss to a minimum. Greater system efficiency maximizes the delivery of heat from each pound of wood. That reduces wood consumption.

  • Easy to install - ThermoPEX is pre-assembled and ready to install
  • Can be installed even in high water table areas
  • Outer casing is UV protected for temporary above ground installations (although interior water lines are not UV protected)
  • Pipe is marked to easily identify supply and return lines

While 1" ThermoPEX is recommended for all installations because of its superior insulation value over all distances, 25 mm ThermoPEX is a good choice in installations with shorter distances. It is flexible, easy to transport and easy to install. Download the 25 mm ThermoPEX Brochure to learn more.

*CTS ASTM 1" supply and return | **CTS ASTM 1-1/4" supply and return | ***CTS ASTM 25 mm supply and return

Download the original ThermoPEX Brochure that features the 1" and 1-1/4" lines.

PEX Specifications