Relax with Reliable Comfort Season After Season.

With a dependable Lennox® oil-fired water boiler from WM J Kraus & Son in Keokuk, you’ll stay warm and toasty—even on winter’s most bitter days. Also, with the addition of an optional tankless coil, your high-efficiency boiler can also provide you with hot water for all your household needs, for only a small cost during the winter months.

See what the COWB3 boiler has to offer.

COWB3 Boiler

Expect years of near-silent heating from the COWB3 boiler. It includes the Beckett® oil burner, which is the standard for reliable fuel-efficient heating.

  • 85.2% AFUE*
  • Optional, domestic tankless hot water coil provides hot water for almost no cost throughout the winter months
  • Sealed combustion design keeps noise at an unnoticeable level
  • Swing-out burner door for simple cleaning and maintenance
  • Compatible with traditional radiator systems
  • Cast-iron heat exchanger for lasting reliability
  • 20-year limited warranty on heat exchanger, 1-year limited warranty on remaining covered parts
COWB3 Boiler
Efficiency Rating (AFUE): up to 85.2

Our boiler professionals at WM J Kraus & Son are available to take care of all your boiler needs, whether you’re looking for a new boiler or boiler maintenance. Call our Keokuk location at 319-524-3714 today, or make your 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.