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Boilers.caby ROMA Heating & Cooling

Comparison

Rinnai RX160iN vs Rinnai RX180iN

Verdict in brief

Rinnai RX160iN and Rinnai RX180iN are two tankless water heaters from the Rinnai SENSEI RX Series line. The Rinnai RX160iN is rated 15–160 MBH input and 0.97 UEF, and the Rinnai RX180iN is rated 15–180 MBH input and 0.98 UEF. Rinnai RX180iN lists 20 MBH more input than Rinnai RX160iN (180 MBH against 160 MBH). Rinnai RX180iN carries the higher published UEF at 0.98 UEF, against 0.97 UEF. Rinnai RX180iN lists 1 lb more shipping weight than Rinnai RX160iN (55 lb against 54 lb).

Side by side

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

Comparison of Rinnai RX160iN and Rinnai RX180iN
SpecificationRinnai RX160iNRinnai RX180iN
Minimum input (hero bullet)15 MBH15 MBH
Maximum input (hero bullet)160 MBH180 MBH
Product weight54 lb55 lb
Water connections3/4 in3/4 in
Gas connection3/4 in3/4 in
Gas typeNatural gas or propane (no conversion kit required)Natural gas or propane (no conversion kit required)
Uniform Energy Factor (UEF)0.97 UEF0.98 UEF
Domestic hot water flow rate (maximum)9 GPM10 GPM
TechnologyCondensing tankless water heaterCondensing tankless water heater
Recirculation capableYesYes
Dimensions (W x H x D)18.5 W x 30.11 H x 11.4 D in18.5 W x 30.11 H x 11.4 D in
Condensate drain1/2" NPT (13 mm)1/2" NPT (13 mm)
Installation typeIndoor or OutdoorIndoor or Outdoor
Wi-Fi capableYesYes
Residential ENERGY STARYesYes
SCAQMD approvedUltra Low NOxUltra Low NOx

What actually separates them

Published ratings: the Rinnai RX160iN is rated 15–160 MBH input and 0.97 UEF; the Rinnai RX180iN is rated 15–180 MBH input and 0.98 UEF. Rinnai RX180iN lists 20 MBH more input than Rinnai RX160iN (180 MBH against 160 MBH). Rinnai RX180iN carries the higher published UEF at 0.98 UEF, against 0.97 UEF.

Rinnai RX180iN lists 1 lb more shipping weight than Rinnai RX160iN (55 lb against 54 lb). The domestic hot water flow rate differs: the Rinnai RX160iN lists 9 GPM, while the Rinnai RX180iN lists 10 GPM.

Both records print the same input (15 MBH), water connections (3/4 in), gas connection (3/4 in) and fuel (Natural gas or propane (no conversion kit required)), per the cited sources.

CurrentSold in Canada
Input
15–160 MBH
Output (max)
—
AFUE
—

The Rinnai RX160iN is a SENSEI RX condensing tankless water heater — a DHW-only appliance, not a boiler — firing 15,000 to 160,000 BTU/h at 0.97 UEF with up to 9 GPM maximum flow.

Natural gasPropaneDHW-only (tankless)
Specifications, manuals and service
CurrentSold in Canada
Input
15–180 MBH
Output (max)
—
AFUE
—

The Rinnai RX180iN is a SENSEI RX condensing tankless water heater — a DHW-only appliance, not a boiler — firing 15,000 to 180,000 BTU/h at 0.98 UEF with up to 10 GPM maximum flow.

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

Frequently asked questions

Which of the two has the higher maximum input?

The Rinnai RX180iN lists 180 MBH, against 160 MBH on the Rinnai RX160iN, per the cited documentation.

Which model is more efficient?

The Rinnai RX180iN carries the higher published UEF at 0.98 UEF, against 0.97 UEF.

How much heavier is the Rinnai RX180iN?

It ships at 55 lb against 54 lb for the Rinnai RX160iN, 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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