Navien NCB-180E Combi Boiler with Tankless Water Heater

Model NCB-180E
4.3/5 from 310 ratings
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Price as of Apr 2026
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Btu
180000
Venting
PVC Direct Vent
Fuel Type
Natural Gas
Tank Type
Combi Boiler
Capacity Gpm
4.2
Dhw Capacity
180 kBTU

Navien NCB-180E Combi Boiler with Tankless Water Heater Review

The Navien NCB-180E is a 180,000 BTU residential combination boiler in Navien's NCB line, providing both space heating and domestic hot water from a single appliance. The "E" designation indicates the Legacy generation (predecessor to the current NCB-A series).

Specs: 180,000 BTU input, AFUE 95% (condensing), 5.4 GPM DHW at a 70°F rise, fully modulating burner with 5:1 turndown. Built-in buffer for DHW function. PVC condensing venting. 15-year warranty on heat exchanger.

The 180K BTU class is sized for medium-sized homes (1,500-2,200 sq ft) with moderate hydronic space-heat demand. Sits below the NCB-210E and NCB-240 in the combi range.

About $7,500-$9,500 installed depending on hydronic system modifications. Right buyer: medium home replacing aging boiler + separate water heater with a single high-efficiency combi unit. The Legacy NCB-180E is parts-supported through 2032 — buying Legacy today saves $200-$400 over the current NCB-180A2 with identical residential performance.

Full Specifications

Brand
Navien
Model Number
NCB-180E
Btu
180000
Venting
PVC Direct Vent
Fuel Type
Natural Gas
Tank Type
Combi Boiler
Capacity Gpm
4.2
Dhw Capacity
180 kBTU
Energy Factor
0.95
Warranty Years
10
Heating Capacity
130 kBTU

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