Enjoy Cozy, Quiet, Efficient Heat for Years to Come with a Gas-Fired Boiler.

Gas-fired water boilers deliver comfortable, even heat almost silently. What’s better is their excellent energy efficiency. At WM J Kraus & Son in Keokuk, many of the Lennox® gas-fired water boilers we offer are ENERGY STAR® qualified.

Explore the details of our high-efficiency boilers.

GWM-IE Boiler

This ENERGY STAR® qualified, gas-modulating condensing water boiler is 40% more efficient than conventional boilers. In fact, it earned a 95% AFUE rating.* To get the most fuel savings, it uses an electronic ignition control that turns on the burner to coordinate with your household demand to ensure it uses only the energy it needs to keep you comfortable.

  • Durable, self-cleaning, stainless steel heat exchanger turns waste energy into usable heat
  • Sealed combustion reduces noise
  • By allowing the burner to fire as low at 20% of its capacity, it’s modulating capability perfectly meets your comfort needs
  • Stainless steel mesh burner fights corrosion and oxidation
  • CPVC flue condensate collector is corrosion-resistant and erases the use of metal in the venting area.
  • 15-year limited warranty on heat exchanger, 10-year limited warranty on remaining covered components
GWM-IE Boiler
Efficiency Rating (AFUE): up to 95
Energy Star badge

GWB9-IH Boiler

The GWB9-IH boiler is easy to integrate with a traditional radiator system and is ENERGY STAR qualified with an AFUE rating of 90%.* Its cast-aluminum heat exchanger carries heat quickly—up to three times faster than a conventional cast-iron exchanger.

  • Enduring, heavy-gauge steel cabinet with baked-on paint finish
  • Compact design for flexibility in installation
  • Sealed combustion keeps noise at a minimum
  • Electronic ignition controls water temperature and turns on the burner only when needed
  • Burns natural gas or can be converted to LP gas
  • 15-year limited warranty on heat exchanger, 10-year limited warranty on remaining covered components
GWB9-IH Boiler
Efficiency Rating (AFUE): up to 90
Energy Star badge

GWB8-IE Boiler

Significantly more efficient than an older boiler, the GWB8 boiler has an 84.4% efficiency rating*—it even works with older radiator systems.

  • Electronic ignition oversees water temperature and turns on the burner only when needed
  • Thick fiberglass insulation greatly reduces off-cycle heat and energy loss
  • Cast-iron heat exchanger and titanium burners engineered for years of durability
  • Offered in six different sizes for ultimate installation flexibility
  • Burns natural gas or can convert to LP gas
  • 20-year limited warranty on heat exchanger, 1-year limited warranty on remaining covered parts
GWB8-IE Boiler
Efficiency Rating (AFUE): up to 84.4

GWB8-E Boiler

This standard-efficiency boiler can perform for years to come with its long-lasting cast-iron heat exchanger and durable stainless steel burners.

  • Electronic ignition oversees water temperature and turns on the burner only when needed
  • Thick fiberglass insulation significantly reduces off-cycle heat and energy loss
  • Compatible with conventional radiator systems
  • Comes in nine different sizes for installation anywhere in your home
  • Burns natural gas or can convert to LP gas
  • 20-year limited warranty on heat exchanger, 1-year limited warranty on remaining covered parts
GWB8-E Boiler
Efficiency Rating (AFUE): up to 83.9

Call us at 319-524-3714 or schedule an appointment online so our team at WM J Kraus & Son in Keokuk can help you find the right boiler for you, or ensure your existing boiler is running as it should.