Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The RX180iN and RX199iN are the two largest SENSEI RX tankless models: both 0.98 UEF, 55 lb and the same cabinet, with the RX199iN firing to 199,000 BTU/h and 11.1 GPM against the RX180iN's 180,000 BTU/h and 10.0 GPM.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Rinnai RX180iN | Rinnai RX199iN |
|---|---|---|
| Minimum input (hero bullet) | 15 MBH | 15 MBH |
| Maximum input (hero bullet) | 180 MBH | 199 MBH |
| Uniform Energy Factor (UEF) | 0.98 UEF | 0.98 UEF |
| Domestic hot water flow rate (maximum) | 10 GPM | 11.1 GPM |
| Product weight | 55 lb | 55 lb |
The RX180iN and RX199iN top the SENSEI RX line, both at 0.98 UEF with a 15,000 BTU/h minimum fire, a 55 lb, 18.5 x 30.11 x 11.4 in cabinet and the same 3/4 in water and gas connections plus 1/2" NPT condensate drain. Both are DHW-only condensing water heaters.
The RX199iN adds 19,000 BTU/h of input ceiling and 1.1 GPM of maximum flow (11.1 against 10.0). In cold-inlet conditions or with several fixtures running at once, that headroom is the reason to choose the larger model; otherwise the two behave alike.
Both install indoors or outdoors, run on natural gas or liquid propane with no conversion kit, and are recirculation-capable, Wi-Fi capable, ENERGY STAR rated and SCAQMD Ultra Low NOx approved. Neither is a boiler; space-heating loads belong on Rinnai's boiler lines or a combi.
Rinnai
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.
Rinnai
The Rinnai RX199iN is a SENSEI RX condensing tankless water heater — a DHW-only appliance, not a boiler — firing 15,000 to 199,000 BTU/h at 0.98 UEF with up to 11.1 GPM maximum flow.
11.1 GPM against the RX180iN's 10.0 GPM, with maximum input rising from 180,000 to 199,000 BTU/h. Both are 0.98 UEF.
Yes. Both weigh 55 lb and measure 18.5 x 30.11 x 11.4 in with identical connections and installation options.
It can serve a household's hot-water demand as a tankless heater, but whether it fits a given home depends on the peak-demand and incoming-water-temperature calculation. A licensed contractor should verify the sizing against the installation manual.
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.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.