Combi Boiler Water Heating & Space Heating
For over 80 years A. O. Smith has been a leader in the water heating industry, A. O. Smith provides energy efficient solutions for water heating needs, including combination boiler water heaters that also provide space heating.
What Our Customers Are Saying
Benefits of Combi Boilers
All-in-One Water & Space Heating
Our high efficiency 95% AFUE combi boilers can replace both a water heater and space heater in your home to save you space, improve performance, and help you save money on operating costs.
Reliable Hot Water Supply
The ProLine® XE Combi Boiler provides industry-leading continuous hot water delivery with its on-demand, high efficiency design.
Superior Space Heating Performance
The ProLine® XE Combi Boiler offers up to 74% more heating capacity than other combination boilers.
Easy to install and maintain, combi boilers feature a compact footprint and a wall-hung design that frees up space in your home.
A. O. Smith combi boilers have a 95% AFUE (Annual Fuel Utilization Efficiency) and are ENERGY STAR® certified, which helps you save money on your energy bills.
Direct venting options up to 100 feet allow for flexibility and easy installation.
How it Works
Combination, or Combi, boilers provide high efficiency space heating and domestic hot water (DHW) in a compact footprint that is easy to install and maintain. When a hot water tap is opened, incoming water flows through the heat exchanger. Heated boiler water, supplied from the fire tube heat exchanger, prioritizes heating the domestic water to the desired temperature. When space heating is needed, a diverter valve directs the heated boiler water into the external space heating loop.
Still Have Questions?
Combi boilers are designed to accomplish both space and water heating with a single appliance. Like a tankless water heater, a combi boiler provides hot water on demand. It can also seamlessly switch between water heating and space heating to provide the best possible experience.
Find A Local Water Heater Pro
A. O. Smith water heaters are professionally installed by local independent contractors.
Interested in Learning More?
Gas water heaters require venting upon installation. Learn more about how to choose the correct vent type for your home.
How Water Quality Affects Water Heaters
How can the quality of your water affect your water heater? Get tips and more information on water hardness, why it matters, and how to solve it.
Why Water Heater Size Matters
Consider what size of water heater is best for your needs. Review the factors you’ll need to weigh before making a decision.
Water Heaters and Safety
Discover the innovative design features A. O. Smith engineers use to keep your water heater both functional and safe for everyday use.
Why A. O. Smith?
A. O. Smith is a leading manufacturer of both residential and commercial water heating technologies, including the #1 most specified commercial water heater.
For more than 145 years, we’ve developed state-of-the art products that push new boundaries and improve the lives of our customers.
We combine cutting-edge technology with committed people who take pride in providing the very best support for our customers.
Our products are put through rigorous quality and endurance testing so now matter where hot water is needed, A. O. Smith can provide a solution you can count on.