Combination Heating & DHW Boilers

Combination boilers that provide both space heating and domestic hot water from one wall-hung unit. The collection includes IBC CX combi boilers at 150,000 and 199,000 BTU with 10:1 turndown, IBC SFC combi boilers from 125,000 to 199,000 BTU at 95% efficiency, and Navien NCB and NFC high-efficiency condensing combi boilers.

Size a combi boiler by both the heating load and the peak hot water demand, since domestic hot water flow usually drives input. Check the minimum firing rate for small zones, venting options, condensate disposal, and the gas line size. Confirm whether a system pump is included.

See also: Condensing Boilers, Water & Space Heating Units (Combi), Navien, Navien Combi Boilers, Navien Boilers.

Frequently asked questions

How do I size a combi boiler?

Check two numbers: the heating input must cover the heat loss, and the hot water side must keep up with the fixtures that run at the same time. Hot water demand usually sets the input.

Combi boiler or boiler with an indirect tank?

A combi saves space because there is no tank. A boiler with an indirect water heater stores hot water and handles several fixtures at once more easily.

Is a system pump included?

It depends on the model. Check the product title and specifications before ordering.