Navien NHB-55H Condensing Heating Boiler, 55,000 BTU, 95% AFUE

The Navien NHB-55H is a compact, wall-hung condensing boiler rated at 55,000 BTU/h input, built for additions, apartments and well-insulated small homes. It modulates up to 11:1 so it can run long and low on mild days instead of short-cycling, which is where oversized boilers waste fuel. Pair it with an indirect tank when you also need domestic hot water.

• 55,000BTU/h input
• 95% AFUEENERGY STAR
• 11:1turndown
• NG / LPfield convertible

Why it earns its place on the wall

• Right-sized heat. Deep modulation matches the burner to the real load for comfort and lower gas bills.
• Dual stainless steel heat exchangers for corrosion resistance.
• Built-in 3-zone controller simplifies multi-zone systems.
• Zero clearance to combustibles and a compact cabinet that fits tight mechanical rooms.
• Field convertible between natural gas and propane.

Specifications

Good to know

• Gas appliances must be installed by a licensed professional following the manufacturer’s installation manual and local codes. Manufacturer warranty terms depend on professional installation and registration.
• Specifications are from the manufacturer. Check the current spec sheet and sizing guide before ordering.
• Large units ship by ground freight. You will receive tracking when your order leaves.
• Questions on sizing or venting? Call +1 901-563-1990 or email support@mouchllc.com before you buy.