The Westinghouse High Efficiency Boiler with Optional Water Heating appliance represents the latest innovation in high efficiency space heating and hot water. This advanced modulating gas condensing boiler has up to 95% AFUE. The condensing boiler is made of a durable high grade stainless steel fire tube heat exchanger and a stainless steel indirect storage tank which eliminates temperature fluctuation. The hi-fin heat exchanger provides high efficiency and a low pressure drop. This wall hung combination appliance saves homeowners money on operating expenses, reduces overall installation costs, and takes up less space than traditional space heating and hot water appliances. It also reduces greenhouse gas emissions by utilizing a mesh burner that reduces nitrogen oxide and carbon monoxide production and meets all nationally recognized low NOx emission standards.