Since 1928, Dunkirk has been producing some of the highest quality, best value Cast Iron Boilers on the market. Our Cast Iron line provides solutions for almost any residential or light commercial hydronic or steam heating applications.
Whether gas or oil, water or steam, Dunkirk has a proven product to meet your heating needs. Each of these boilers include features and benefits that make them easy to install and maintain. Our convenient product selector will help find the right Dunkirk boiler for you.

Cast Iron Quality

Cast iron push nipples and heat exchangers provide maximum heat transfer and superior durability. Since like materials expand and contract in the same proportion during heating and cooling, cast iron push nipples and sections produce stronger, more water-tight seals than steel push nipples or rubber gaskets.

99.91% Reliability

Assured performance has placed Dunkirk Boiler quality at the top in trusted reliability, that's why we use Honeywell controls. Dunkirk Boilers are also certified. Gas boilers are certified by AGA (American Gas Association). The heat exchangers are certified by ASME; and efficiency ratings by the Hydronics Institute. Most models also available with CGA or CSA (Canadian) certification.

Strongest Warranty in the Industry

Dunkirk backs all of its cast iron residential boilers with NON-PRORATED WARRANTIES, 20 year water and 12 year steam, covering the entire heat exchanger. Most other warranties cover sections of the heat exchangers. In addition, you may want to top off your boiler purchase with Dunkirk's Customer Assurance Program.
The purchase of this extended 5-Year Parts and Labor Warranty will guarantee peace of mind and financial security against those unexpected malfunctions. The C.A.P. Warranty covers the cost of replacement parts and labor for five (5) years from the date of initial installation.

So Easy to Install