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Comparison

Navien NPE-150S2 vs Navien NPE-210S2

Verdict in brief

The Navien NPE-150S2 and Navien NPE-210S2 are both tankless water heaters in the Navien NPE-S2 Tankless Water Heaters (DHW) line. Published ratings: Navien NPE-150S2 at 18–120 MBH input and 0.93 UEF; Navien NPE-210S2 at 12–180 MBH input and 0.96 UEF. Navien NPE-210S2 lists 60 MBH more input than Navien NPE-150S2 (180 MBH against 120 MBH). Navien NPE-210S2 carries the higher published UEF at 0.96 UEF, against 0.93 UEF. Navien NPE-210S2 lists 11 lb more shipping weight than Navien NPE-150S2 (73 lb against 62 lb).

Side by side

Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.

Comparison of Navien NPE-150S2 and Navien NPE-210S2
SpecificationNavien NPE-150S2Navien NPE-210S2
Input, minimum18 MBH12 MBH
Input, maximum120 MBH180 MBH
Weight62 lb73 lb
Height27.4 in27.4 in
Width17.3 in17.3 in
Depth13.2 in13.2 in
Water connections3/4" NPT3/4" NPT
Gas connection3/4" NPT3/4" NPT
FuelNatural gas or propaneNatural gas or propane
Uniform Energy Factor (UEF)0.93 UEF0.96 UEF
Maximum flow rate at 35°F (19.4°C) rise6.8 GPM10.1 GPM
Technologycondensing tankless water heatercondensing tankless water heater
RecirculationField recirculation options per the NPE-2 installation manualField recirculation options per the NPE-2 installation manual
InstallationIndoor or outdoor wall-hungIndoor or outdoor wall-hung
ApprovalsCSA; NSF/ANSI 5; SCAQMD 1146.2 (NOx < 20 ppm); AHRI listed per modelCSA; NSF/ANSI 5; SCAQMD 1146.2 (NOx < 20 ppm); AHRI listed per model

What actually separates them

Published ratings: the Navien NPE-150S2 is rated 18–120 MBH input and 0.93 UEF; the Navien NPE-210S2 is rated 12–180 MBH input and 0.96 UEF. Navien NPE-210S2 lists 60 MBH more input than Navien NPE-150S2 (180 MBH against 120 MBH). Navien NPE-210S2 carries the higher published UEF at 0.96 UEF, against 0.93 UEF.

Navien NPE-210S2 lists 11 lb more shipping weight than Navien NPE-150S2 (73 lb against 62 lb). The maximum flow rate at 35°F rise differs: the Navien NPE-150S2 lists 6.8 GPM, while the Navien NPE-210S2 lists 10.1 GPM.

Both records print the same height (27.4 in), width (17.3 in), depth (13.2 in) and water connections (3/4" NPT), per the cited sources.

CurrentSold in Canada
Input
18–120 MBH
Output (max)
—
AFUE
—

The Navien NPE-150S2 is a condensing tankless water heater — a DHW-only appliance, not a boiler — firing 18,000 to 120,000 BTU/h at 0.93 UEF with up to 6.8 GPM at a 35°F rise.

Natural gasPropaneDHW-only (tankless)
Specifications, manuals and service
CurrentSold in Canada
Input
12–180 MBH
Output (max)
—
AFUE
—

The Navien NPE-210S2 is a condensing tankless water heater — a DHW-only appliance, not a boiler — firing 12,000 to 180,000 BTU/h at 0.96 UEF with up to 10.1 GPM at a 35°F rise.

Natural gasPropaneDHW-only (tankless)
Specifications, manuals and service

Frequently asked questions

Which of the two has the higher maximum input?

The Navien NPE-210S2 lists 180 MBH, against 120 MBH on the Navien NPE-150S2, per the cited documentation.

Which model is more efficient?

The Navien NPE-210S2 carries the higher published UEF at 0.96 UEF, against 0.93 UEF.

How much heavier is the Navien NPE-210S2?

It ships at 73 lb against 62 lb for the Navien NPE-150S2, per the cited sources.

Not sure which one fits your home?

A consultation includes a heat-loss review so the size is right the first time.

On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.

Call 778-909-5731Request a consultation

Related

Sources and verification

Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.

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