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Comparison

Rinnai RU199iN vs RXP199iN: External Pump or Built-In?

Verdict in brief

Both are 15,000–199,000 BTU/h indoor condensing natural-gas tankless units, but from different Rinnai platforms. The RU199iN is SENSEI RU at UEF 0.95, with Circ-Logic recirculation through an external pump. The RXP199iN is the RX platform's pump-included flagship at UEF 0.98, with the recirculation pump built into the cabinet. Choose the RXP199iN when a recirculation loop is planned and you want the pump integrated; choose the RU199iN when recirculation is not needed now, or will be added later with a separate pump.

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 Rinnai RXP199iN
SpecificationRinnai RU199iNGas tanklessRinnai RXP199iNGas tankless
Minimum gas input15,000 BTU/h15,000 BTU/h
Maximum gas input199,000 BTU/h199,000 BTU/h
Maximum flow with parameter adjustment11 GPM (42 L/min) at unspecified rise rise11.1 GPM (42 L/min) at unspecified rise rise
Minimum activation flow0.4 GPM (1.5 L/min)0.4 GPM (1.5 L/min)
Uniform Energy Factor (UEF)0.950.98
Outlet temperature setting37–49 °C (98–120 °F) default; up to 60 °C (140 °F) with parameter adjustment37–49 °C (98–120 °F) default range
Vent material2 in PVC/CPVC/polypropylene or 3 in/5 in concentricPVC, CPVC or polypropylene (condensing)
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)1/2 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, 60 Hz
RecirculationCapable with external pump (Circ-Logic); no built-in pumpBuilt-in recirculation pump
Height26.4 in (670 mm) cabinet; 31.3 in (795 mm) with fittings per rinnai.ca30.11 in (762 mm)
Width18.5 in (470 mm)18.5 in (470 mm)
Depth11.4 in (290 mm)11.4 in (291 mm)
Weight64 lb (29 kg)58 lb (26.3 kg)
CertificationANSI Z21.10.3 / CSA 4.3; SCAQMD ultra-low NOxSCAQMD ultra-low-NOx approved

“—” 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

Efficiency is the clearest split: rinnai.ca publishes UEF 0.98 for the RXP199iN against UEF 0.95 for the RU199iN, and the RU sheet also lists a legacy EF of 0.96 that is a different test and must not be mixed with UEF. Both are high-draw-class ratings on the same site, so the 0.03 gap is directional rather than a savings percentage.

Flow is quoted the same way on both pages and carries the same caution. The RU199iN is rated 0.26–9.8 GPM (1.0–37 L/min) and adjustable to 11 GPM (42 L/min); the RXP199iN is listed at 11.1 GPM (42 L/min) maximum. Neither page states the temperature rise behind the headline, and Rinnai's curves apply to inlet water at 21 °C or below, so in Metro Vancouver winter at roughly a 40 °C rise to a 49 °C shower the deliverable flow is far lower than either figure. Both fire down to 0.4 GPM (1.5 L/min).

Recirculation is the practical difference. The RXP199iN carries the recirculation pump inside the cabinet, so a return line needs no separately mounted pump or pump cable; the RU199iN supports recirculation through Rinnai's Circ-Logic with an external pump and either a dedicated return line or a crossover valve, with the pump cable sold separately. Recirculation shortens the wait at distant taps and adds gas use; it does not make hot water instant.

The cabinets differ in an unexpected direction. The RU199iN is 26.4 in (670 mm) to the cabinet, or 31.3 in (795 mm) including fittings, at 64 lb (29 kg); the RXP199iN is taller at 30.11 in (762 mm) but lighter at 58 lb (26.3 kg), with the same 18.5 in width and 11.4 in depth. Both take 3/4 in gas and water connections, a 1/2 in NPT condensate drain, 120 V power and PVC, CPVC or polypropylene condensing venting, and annual descaling remains a warranty condition on both. Rinnai's main tankless listing now leads with the RX and RXP families, so current availability of a given RU model is confirmed before ordering. Whether CANRO supplies either 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

Rinnai · Gas tankless

Rinnai RXP199iN

CurrentSold in Canada
Max input
199,000 BTU/h
Flow at unspecified rise rise
11.1 GPM (42 L/min)
Uniform Energy Factor (UEF)
0.98

The Rinnai RXP199iN is the RX199iN with a built-in recirculation pump: 15,000–199,000 BTU/h, UEF 0.98, up to 11.1 GPM (42 L/min) maximum flow, Wi-Fi control and ENERGY STAR marked on rinnai.ca. It is Rinnai Canada's pump-included flagship.

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

Frequently asked questions

What does the P in RXP199iN mean?

The pump: the RXP199iN has the recirculation pump built in, where the RU199iN supports recirculation only with an external pump. That is the main functional difference between the two units.

Is the RXP199iN more efficient than the RU199iN?

Yes, on Rinnai's published figures: UEF 0.98 against UEF 0.95. Both are high-draw-class ratings, and the RU sheet's legacy EF of 0.96 is a different test that should not be compared with either UEF.

Which one gives more hot water in winter?

Both are capped at 199,000 BTU/h, and neither page states a rise behind its flow headline, so the winter delivery depends on the actual incoming water temperature. The flow-at-rise tables in the installation manuals, not the adjusted maximum, decide simultaneous-fixture performance.

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 21, 2026. Last updated September 21, 2026. Technical reviewer: not yet assigned.

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