Water heaters
Rinnai RE180iN Non-Condensing Gas Tankless Water Heater
Prices are the equipment only — the appliance, before install labour. Every product in this catalogue currently has at least one real, seller-observed equipment price (see the SKU verification and price observation notes on each product). Get contractor quotes for the install itself, especially for anything needing new electrical circuits or condensate drainage.
Rinnai's non-condensing indoor gas tankless: 8.5 GPM max flow, UEF 0.82, 180,000 BTU/h, a 5-year parts warranty with a separate 15-year heat-exchanger term. Not ENERGY STAR rated.
Our take
This is Rinnai's non-condensing tankless, the cheaper way into gas tankless when a condensate drain isn't already run to wherever the unit sits -- no condensing means no acidic condensate to manage, which is a real installation-cost saving in a retrofit. The UEF number is where you pay for that simplicity: 0.82 against the RX160iN's 0.93 and the Navien NPE-240A2's 0.95, both already in this catalog. Same warranty shape as those condensing units -- 5 years parts, plus Rinnai's 15-year heat-exchanger term here -- but you're burning noticeably more gas per gallon of hot water over the unit's life.
Best for
Gas homes doing a tankless retrofit where running a condensate drain isn't practical or affordable, and the extra 11-13 points of UEF against the condensing options isn't worth the plumbing work.
Watch out for
Rinnai's own published flow rating is a straight 8.5 GPM maximum, not tied to a specific temperature rise the way this site's other tankless entries are -- no source found ties it to a 35°F rise specifically, so don't compare that number directly against the RX160iN's or NPE-240A2's 35°F-rise GPM figures without asking your installer to translate it for your actual groundwater temperature.
What sellers are actually charging
The lowest in-stock, full-equipment price we've seen is $1,091, at Home Depot, seen 2026-08-30. Every listing from the last 30 days, newest first, is below — prices change, click through to check before you act on any of them.
| Seller | What you get | Price | Stock | Seen |
|---|---|---|---|---|
| Lowe's
big box retailer |
equipment system | $1,212 | in stock | 2026-08-30 |
| Home Depot
big box retailer |
equipment system | $1,091
|
in stock | 2026-08-30 |
Equipment price is not installed price. The listings above are what the hardware costs. Installation — labour, electrical, refrigerant lines, permits, removing the old system — is typically a similar amount again, and varies more between contractors than between brands. Where we have an installed figure it is labelled as such and comes from someone who actually installs.
Before you buy — install and sizing lessons
Reported issues about installation, sizing, or the dealer/installer — not the equipment itself. These don't affect the ratings above; they're what to ask your contractor about before you sign a contract.
Installation and commissioning · house fit
Newly installed RE180iN kept shutting off on a gas-related error (code 12) within hours of a certified-contractor install; per Rinnai support and a knowledgeable forum reply, root cause was insufficient house gas-line pressure/sizing, not a unit defect.
"Newly installed unit keeps shutting off flashing code12 (gas issue) after several hours of being installed by certified Rinnai contractor." — ColdHeater homeowner, 2023-11
Rinnai RE180iN · HeatingHelp — The Wall · 2023-11 · read it in context
Compare against
Navien NPE-240A2 Condensing Tankless Water Heater
Condensing gas tankless water heater, UEF 0.95, 11.2 GPM at a 35°F rise — Navien's mid-large residential model, ENERGY STAR certified.
Rinnai RX160iN Condensing Tankless Water Heater
Condensing gas tankless water heater, UEF 0.93, endless hot water with no standby loss.
Rheem ProTerra Hybrid Heat Pump Water Heater, 50 gal
The default heat pump water heater for most US households: 50 gallons, UEF 3.75, widely stocked and widely serviced.
Rheem ProTerra Hybrid Heat Pump Water Heater, 80 gal
80-gallon version of the ProTerra, UEF 4.0 — the highest efficiency in the mainstream heat pump water heater market.
Before you buy this
Ask for the first-hour rating, not just tank size, and check it against your household's simultaneous demand — showers and laundry at the same time — rather than headcount alone. If it's a heat pump water heater, confirm the room has enough air volume (or a duct kit) that it won't spend winter on resistance backup, and that there's a real route for condensate, not just a nearby floor drain. Confirm the panel has spare 240V capacity. And if you're removing a gas unit that shared a flue with a furnace, ask what happens to that flue once your water heater's draft is gone — an orphaned flue can backdraft.