Relax with Reliable Comfort Season After Season.

With a reliable Lennox® oil-fired water boiler from Twin Air LLC in Manassas, you’ll stay warm and toasty—even on winter’s most bone-chilling days. Also, when you add an optional tankless coil, your high-efficiency boiler can also make hot water for all your household needs, at virtually no cost during the winter months.

Find out more about what the COWB3 boiler has to offer.

COWB3 Boiler

You will enjoy years of ultraquiet performance from the COWB3 boiler. It is made with the Beckett® oil burner, which is the standard for reliable fuel-efficient heating.

  • 85.2% AFUE*
  • Optional, domestic tankless hot water coil heats hot water for very little cost throughout the cold season
  • Sealed combustion design keeps noise at an unnoticeable level
  • Swing-out burner door for easy cleaning and maintenance
  • Works 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 pros at Twin Air LLC are always ready to help with all your boiler needs, whether you need a new boiler or boiler maintenance. Call our Manassas location at 703-754-1062 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.