Best Combi Boilers for Nassau County

For Nassau County, we recommend comparing Navien and Rinnai based on heat loss, simultaneous hot-water demand, venting, water quality, controls, local parts support, and budget. Their AFUE ratings do not automatically establish eligibility for a utility or manufacturer program.

Combi boiler installation on Long Island typically costs $5,500-$9,000 including the unit and labor. Compare that installed range with the scope and price of separate boiler and water-heater options. Any current utility or manufacturer incentive must be confirmed in writing for the customer, equipment, project, contractor, funding availability, and current program rules before it is reflected in a quote.

Combi boilers work best for 1-2 bathroom homes under 2,000 sq ft—which describes many Cape Cods in Levittown, Hicksville, and Bethpage. If you have 3+ bathrooms or frequently run multiple hot water fixtures simultaneously, we recommend separate high-efficiency boiler and tankless water heater instead.

All condensing equipment, including combis, requires annual descaling due to Long Island's hard water. Navien and Rinnai have built-in scale detection that alerts you to issues before damage occurs. We include descaling in our maintenance plans for all combi installations.