Commercial Gas Hot Water Supply Boilers
A. O. Smith’s line of Conservationist® Burkay® high efficiency commercial gas hot water supply boilers are designed for indoor high input commercial applications using a patented design to maximize combustion efficiency.
Hot Water Supply Boilers
Conservationist® Burkay® high efficiency gas circulating water heaters are designed for indoor use in installations requiring higher inputs (up to 670,000 Btu). They’re rust-proof because water comes in contact with nothing but copper, brass or bronze. And the Burkay burner features a patented design that maximizes combustion efficiency.
Product Documents
Spec Sheet - Burkay Hot Water Supply Boiler (aosdg25600) 
- HW 300, HW 399, HW 420, HW 520, HW 670 Nat, HW 670 Prop
Never let your business
run out of hot water.
24/7 same-day water heater repair or replace for your business.
Replacement Parts
Finding replacement parts for A. O. Smith's commercial water heater products is easy thanks to our wide selection and online parts portal.
Commercial Sizing Tool
Use our tool to size an A. O. Smith commercial water heater to meet your specs.
Water Heater Resources
Find detailed product literature, a water heater sizing tool, virtual training workshops, a product cross-reference tool, and other valuable information on our resource page. Partner with A. O. Smith to help your business thrive.
Commercial Sizing Tool
Use our tool to size an A. O. Smith commercial water heater to meet your specs.
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.