A Versatile Gas-Fired Steam Boiler For Your Unique Home. If you’re looking for a new gas-fired steam boiler (or for an expert to fix your existing steam boiler) in the Marshalltowncommunity, B & G HVAC is here to help. We sell the Lennox® GSB8-E, which comes with a diverse menu of benefits. GSB8-E BoilerThis steam boiler is superior to its competition with an 82.7% AFUE rating* and notable components like a cast-iron heat exchanger and titanium burners. For many years of comfortable heat, look at the GSB8-E. Electronic ignition controls water temperature and ignites the burner only when needed Vent damper bolsters efficiency by closing automatically when the boiler shuts off Thick fiberglass insulation helps minimize off-cycle heat and energy loss Burns natural gas or convertible to LP gas Will work with traditional radiator and underfloor heating systems Electronic low water cut-off Large steam chest and multiple supply connections reduce noise Available in seven different sizes to fit your home’s individual needs 12-year limited warranty on heat exchanger, 1-year limited warranty on remaining covered parts Efficiency Rating (AFUE): up to 82.7 Product Brochure Contact Us to Learn More B & G HVAC in Marshalltown is always ready to help you with a new high efficiency boiler! Call us at 641-812-2044 or create an appointment online. *Annual Fuel Utilization Efficiency (AFUE) measures how efficient the appliance is in converting its fuel’s energy into heat over the course of a year.