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Written from the listing's specs, not from our own use · How we rate
The Rinnai RUCS65IP Propane is an indoor gas tankless heater built around a 6.5 GPM maximum flow. It is a good match for one shower plus the kitchen in a typical family morning, at 7.0/10 on its documented specs.
| Brand | Rinnai |
|---|---|
| Category | Gas tankless water heaters |
| Fuel | Propane |
| Stated mounting location | Indoor |
| Stated maximum flow | 6.5 GPM |
| Stated warranty | 1 years |
| ASIN | B010Q1XDC4 |
Full listing title: Rinnai RUCS65IP Tankless Hot Water Heater, Propane
| Fuel | PropaneFull listing title |
|---|---|
| Stated mounting location | RUCS65IPFull listing title (Rinnai model suffix: i = indoor, e = exterior) |
| Stated maximum flow | up to 6.5 GPMListing text |
Rated from the listing's specs, no buyer reviews yet
What it's made for: one shower plus the kitchen in a typical family morning.
Two gas tankless heaters on propane too, with about the same flow, closest to it on our rating, each with a dated price.
That's the maximum flow the listing states, and headline flows are usually quoted at a mild temperature rise. With January water coming in at 42 °F and a 105 °F shower, the rise is 63 °F and the real flow is lower; the maker's flow chart has that number. At 2 GPM a shower (our calculator's figure), the headline means two showers and a kitchen tap, less when the water comes in cold.
One at a time, plus the kitchen tap: 6.5 GPM covers that on paper.
Two at once: possible where the tap water comes in warm. In a northern January the second shower is the one that runs lukewarm, so read the flow chart at a 63 °F rise first.
What the Rinnai RUCS65IP Propane listing names:
Warranty & support: 1-year warranty, as stated in the listing.
That is the maker's promise, not ours. Keep the invoice, register the Rinnai RUCS65IP Propane if the maker asks, and read the install conditions: many tankless warranties need a licensed install and regular flushing.
For the Rinnai RUCS65IP Propane, the installation manual settles the venting, the gas line and the clearances.
At the price on Sep 30, 2026, each GPM of stated maximum flow works out at about $130.62 (price ÷ stated GPM, our arithmetic). That puts it around the middle of the 45 indoor gas tankless heaters we have a price and a stated flow for.
The online price is the heater alone. Venting, a bigger gas line where needed and the installer's day are a separate bill, often as big as this one.
The button opens the exact listing (ASIN B010Q1XDC4), where today's price, stock and seller apply.
Two showers and the dishwasher at once? The MIZUDO 199,000 BTU Natural Gas Indoor (9.2/10) states up to 10.3 GPM.
No easy route for a vent pipe? The Ranein 130,000 BTU Propane Outdoor (7.5/10) mounts on an outside wall, per its listing.
Want the high-efficiency kind? The ThermoMate Condensing Propane (7.6/10) is a condensing unit rated 0.86 UEF, per its listing.
Our take
The Rinnai RUCS65IP Propane is about a 6.5 GPM maximum flow, and it doesn't pretend to be more. No buyer reviews yet, so the Rinnai RUCS65IP Propane has to win you over on paper. The catch with this Rinnai indoor gas tankless heater: no stated temperature hold, while most picks here claim ±1 °F. We'd pick it if you run one shower and the kitchen tap at once, rarely more; otherwise, put it next to the Rheem RTG 7.0 GPM Natural Gas Indoor first.
Old tank out, unit on the wall, vent through the wall or the roof. a licensed pro handles it, and often a permit.
Hot water arrives after the cold already in the pipes, then stays. A trickle from a bathroom tap may not light the burner; open it a bit more.
January water comes in colder, so the same unit gives fewer GPM. Stagger the showers if you sized it tight.
Flush the heat exchanger with a pump and a descaler (the service valves make it an hour's job), and clean the inlet filter. Our flushing and descaling guide has the checklist.
Before the Rinnai RUCS65IP Propane ships, check your winter flow: 6.5 GPM is a best case, so run your January numbers in our calculator first.
Count the fixtures that run together on a busy morning (our calculator uses 2 GPM a shower, 1.5 for the kitchen), then compare with the maker's chart. Our sizing guide shows how.
A licensed plumber or gas fitter confirms the vent route, the combustion air and a gas line that can deliver its full input. Get that quote before you order; our installation guide lists what they will ask.
1 years are stated. Read what it requires: a licensed install, the gas type and regular flushing are the usual conditions.
Hard water scales the heat exchanger. Service valves on the water lines turn the yearly flush into an hour with a bucket and a pump; our flushing and descaling guide shows the routine.
How the Rinnai RUCS65IP Propane stacks up against the closest alternative, the Rheem RTG 7.0 GPM Natural Gas Indoor.
| Criterion | Rinnai RUCS65IP Propane | Rheem RTG 7.0 GPM Natural Gas Indoor |
|---|---|---|
| Our rating | 7.0/10 | 7.0/10 |
| Max flow | 6.5 GPM | 7 GPM |
| Gas input | Not stated | 160,000 BTU/h |
| Temperature hold | Not stated | ±1 °F stated |
| Warranty | 1 years | Not stated |
| Buyer reviews | None captured | 65 · 4.5/5 |
Both score 7.0/10. The Rheem RTG 7.0 GPM Natural Gas Indoor adds more flow (7 GPM) and a bigger burner (160,000 BTU/h), while the Rinnai RUCS65IP Propane brings a longer stated warranty (1 years).
We rate it 7.0/10 (good). The rating comes from its documented listing alone, as no customer-review record is captured yet.
The listing states a maximum flow of 6.5 GPM. The headline flow is a mild-weather number: with cold winter water coming in, the same unit gives you less. Read the maker's flow chart at your winter rise, or let our flow-rate calculator do the sums.
Yes, the listing says indoor mounting. That means a vent route to the outside, combustion air and a gas line sized for the unit, all as the maker and your local code require. A licensed plumber or gas fitter sorts that out.
Its listing states up to 6.5 GPM. These are the seller's figures, not our measurements: how steady the temperature is in your shower and how it copes with your winter water can't be read from a listing.
Your winter flow: count the fixtures that run together on a busy morning (our calculator uses 2 GPM a shower, 1.5 for the kitchen), then compare with the maker's chart. Our sizing guide shows how. Vent and gas line: a licensed plumber or gas fitter confirms the vent route, the combustion air and a gas line that can deliver its full input. Get that quote before you order; our installation guide lists what they will ask. The warranty terms: 1 years are stated. Read what it requires: a licensed install, the gas type and regular flushing are the usual conditions. Flushing: hard water scales the heat exchanger. Service valves on the water lines turn the yearly flush into an hour with a bucket and a pump; our flushing and descaling guide shows the routine.
We link to the exact listing on Amazon, where today's price, stock and seller apply. It is an affiliate link, and it has no effect on the rating.
No, we haven't used it ourselves. Everything on this page comes from its listing, read line by line and weighed with our published formula.