4" to 3" Reducer for Innoflue SW

4" to 3" Reducer for Innoflue SW

The ISRD0403 from Centrotherm is a 4” to 3” Reducer for Innoflue SW pipes. This adapter allows to reduce Innoflue SW pipe size from 4" to 3". Suitable for vertical or horizontal installation. For horizontal runs, install only with eccentric portion at the very top.


  • Innoflue SW (Single Wall) is the only polymer vent system on the market listed to UL 1738;
  • Accepted and approved by over 50 North Amercian manufacturers of boilers, water heaters and furnaces;
  • Suitable for natural gas, propane and fuel-oil condensing and non-condensing (flue temp. below 248°F) appliances;
  • All parts (pipe, fittings, etc. - both black and grey) are UV resistant and suitable for indoor or outdoor installation;
  • Requires no primer/glue and does not leach chloride like PVC & CPVC;
  • Costs less and is faster and easier to install than stainless steel venting, no special tools needed, zero clearance to combustibles;
  • Industry-leading 2mm wall thickness;
  • Built-in gasket allows for adhesive-free installation which can be adjusted at any time;
  • May be installed through a wall, chimney, chase or between joists;
  • Lightweight, requires minimal support;
  • Made in the USA from environmentally-friendly PolyPropylene (PP).
Product Specs
Size1 3";4"

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  • Views: 6116
  • 4" to 3" Reducer for Innoflue SW QR Code
  • Model: ISRD0403
  • MPN: ISRD0403
  • Availability: Discontinued
  • $ 49.95


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Tags: Vent Pipes, Heating, Heating Supplies, Condensing Boilers, Heating and Cooling