Weil-McLain’s GV90+ series of gas boilers presents a unique option for hydronic heating systems: cast iron condensing boilers. Condensing boilers can handle condensed flue gases when return water temperatures are sufficiently low, resulting in less waste and higher efficiency ratings. Traditional cast iron boilers would be damaged by this acidic condensate, but the GV90+ includes a stainless steel heat exchanger to accommodate the condensate. The ability to condense flue gases allows all models in the series to boast DOE AFUE efficiency ratings of 91% or higher.
The boilers are also compatible with PVC venting and can be vented vertically or horizontally. They are ideal for high-temperature hydonic systems. They use two internal circulator pumps and an integrated control module to ensure that return fluid temperatures are low enough to allow flue gases to condense. LP conversion kits come standard with all GV90+ models.