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Comparison

Rinnai RU199iN vs Navien NPE-240S2 (199,000 BTU/h condensing tankless)

Verdict in brief

These are the flagship residential condensing tankless units from the two brands most often compared in Metro Vancouver, and they share the 199,000 BTU/h class: the Rinnai RU199iN is 15,000–199,000 BTU/h at UEF 0.95 and the Navien NPE-240S2 is 13,300–199,900 BTU/h at UEF 0.96. Both take 2 in PVC-family venting, both connect to 3/4 in gas and water, and both run on 120 V. The honest difference is how they publish flow: Navien states flow at 35/45/67 °F rises (5.8 GPM at 67 °F), while Rinnai states 9.8 GPM rated and 11 GPM adjusted with no rise attached, so only Navien's at-rise figures can be read directly as winter performance.

Side by side

Published manufacturer figures with units. Storage and flow figures are different measures and are shown on their own rows; blanks mean not applicable or not published.

Comparison of Rinnai RU199iN and Navien NPE-240S2
SpecificationRinnai RU199iNGas tanklessNavien NPE-240S2Gas tankless
Minimum gas input15,000 BTU/h13,300 BTU/h
Maximum gas input199,000 BTU/h199,900 BTU/h
Rated flow range0.26–9.8 GPM (1.0–37 L/min) at unspecified rise rise—
Maximum flow with parameter adjustment11 GPM (42 L/min) at unspecified rise rise—
Flow at a 35 °F (19.4 °C) rise—11.2 GPM (42.4 L/min) at 35 °F (19.4 °C) rise
Flow at a 45 °F (25 °C) rise—8.7 GPM (32.9 L/min) at 45 °F (25 °C) rise
Flow at a 67 °F (37.2 °C) rise—5.8 GPM (22.0 L/min) at 67 °F (37.2 °C) rise
Minimum activation flow0.4 GPM (1.5 L/min)0.5 GPM (1.9 L/min)
Uniform Energy Factor (UEF)0.950.96
Vent material2 in PVC/CPVC/polypropylene or 3 in/5 in concentric—
Vent type—2 in or 3 in PVC, CPVC, approved polypropylene or stainless steel; special gas vent type BH (Class II A/B/C)
Gas connection3/4 in MNPT (19 mm)3/4 in
Water connections3/4 in MNPT cold in and hot out3/4 in cold inlet and hot outlet
Condensate drain1/2 in NPT (13 mm)—
Electrical supply120 V, 60 Hz; 84 W normal, 1.3 W standby, 148 W with freeze protection; 4 A max, 10 A fuse120 V AC, 60 Hz
Height26.4 in (670 mm) cabinet; 31.3 in (795 mm) with fittings per rinnai.ca27.4 in (696 mm)
Width18.5 in (470 mm)17.3 in (439 mm)
Depth11.4 in (290 mm)13.2 in (335 mm)
Weight64 lb (29 kg)73 lb (33.1 kg)
Maximum altitude10,200 ft (3,109 m)10,100 ft for natural gas and propane
CertificationANSI Z21.10.3 / CSA 4.3; SCAQMD ultra-low NOxFlame rod, air-pressure switch, ignition-operation detector and high-limit devices per Navien's specification table

“—” means not applicable to that system type or not published by the manufacturer. Flow figures are only comparable at the same temperature rise; UEF values are only comparable within the same draw pattern.

What actually separates them

Both are indoor, wall-hung, condensing, natural-gas units in the same input class. Rinnai rates the RU199iN at UEF 0.95 (with a legacy EF of 0.96 that is a different test); Navien rates the NPE-240S2 at UEF 0.96. Both accept 2 in PVC, CPVC or polypropylene condensing venting, both have a 3/4 in gas connection and 3/4 in water connections, both drain condensate through a 1/2 in NPT connection, and both run on 120 V.

The sizing comparison turns on how each manufacturer states flow. Navien publishes flow at three temperature rises, including 5.8 GPM (22.0 L/min) at the 67 °F (37.2 °C) rise that matches a Metro Vancouver winter. Rinnai publishes a 9.8 GPM rated flow and an 11 GPM adjusted maximum with no temperature rise, valid only for inlet water at 21 °C or below; its at-rise performance is read from the flow curves in manual 100000467. Putting 11 GPM beside 5.8 GPM would be comparing a warm-inlet maximum against a winter-class figure, which is why the table leaves the rise rows blank for the Rinnai unit.

Minimum input and activation differ slightly. The NPE-240S2 modulates down to 13,300 BTU/h and fires from 0.5 GPM (1.9 L/min); the RU199iN modulates down to 15,000 BTU/h and fires from 0.4 GPM (1.5 L/min). The lower Navien minimum can matter for very low-flow fixtures and small draws, and the lower Rinnai activation threshold can matter for the opposite reason.

Physically the Navien cabinet is deeper and heavier (13.2 in deep, 73 lb / 33.1 kg) against the Rinnai unit (11.4 in deep, 64 lb / 29 kg), while Rinnai's published height varies between the 26.4 in cabinet and 31.3 in with fittings. Both support recirculation with an external pump and neither carries a built-in pump at this model; the Rinnai RUR199iN and the Navien recirculation accessories are the pump options. Whichever brand a household is drawn to, the model is chosen from measured simultaneous flow and the gas supply and vent route are confirmed first. Whether CANRO stocks a given model for a job is confirmed at consultation.

Rinnai · Gas tankless

Rinnai RU199iN

CurrentSold in Canada
Max input
199,000 BTU/h
Flow at unspecified rise rise
11 GPM (42 L/min)
Uniform Energy Factor (UEF)
0.95

The Rinnai RU199iN is an indoor condensing natural gas tankless water heater with a 15,000–199,000 BTU/h input, UEF 0.95, 2" PVC venting and up to 11 GPM (42 L/min) of flow at an unstated temperature rise. It is listed on rinnai.ca and is the largest residential RU model, with a propane version, the RU199iP.

Natural gasPropaneCondensing, PVC/CPVC/PP
Specifications, manuals and service

Navien · Gas tankless

Navien NPE-240S2

CurrentSold in Canada
Max input
199,900 BTU/h
Flow at 35 °F (19.4 °C) rise
11.2 GPM (42.4 L/min)
Uniform Energy Factor (UEF)
0.96

The Navien NPE-240S2 is the largest of Navien's current S2 condensing tankless models: 13,300–199,900 BTU/h on natural gas or propane, UEF 0.96, and published flows of 11.2 GPM at a 35 °F rise and 5.8 GPM at a 67 °F rise.

Natural gasPropaneCondensing, PVC/CPVC/PP
Specifications, manuals and service

Frequently asked questions

Which is more efficient, the RU199iN or the NPE-240S2?

Navien publishes UEF 0.96 for the NPE-240S2 against Rinnai's 0.95 for the RU199iN. Both are high-draw-class ratings and the gap is one point, not a savings percentage, and neither should be compared with a legacy EF.

Can I compare their flow directly?

Only carefully. Navien publishes flow at 35/45/67 °F rises, so 5.8 GPM at 67 °F is a winter-class figure; Rinnai publishes 11 GPM with no rise, valid only for warm inlet water. Compare both at the same rise from each manual's curves.

Do both need the same installation?

Both need 2 in PVC-family sealed venting, a 3/4 in gas connection sized for about 199,000 BTU/h, a condensate drain and a 120 V outlet. The vent route and gas supply are confirmed for the address before either is specified.

Not sure which one fits your home?

A consultation includes a hot-water demand review so capacity is right for your winter, not the brochure's.

On-site service in Metro Vancouver, BC. Call to check availability.

Call 604-359-1081Request a consultation

Related

Sources and verification

Facts checked September 7, 2026. Last updated September 20, 2026. Technical reviewer: not yet assigned.

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