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Written from the listing and 5 buyer reviews, not from our own use · How we rate
The Noritz NR66ODLP Outdoor Propane ticks most of the boxes we care about: a 6.6 GPM maximum flow and outdoor mounting that skips the flue. A good match for a two-bathroom house with one shower running at a time, with 5 buyer reviews averaging 4.0/5.
| Brand | Noritz |
|---|---|
| Category | Gas tankless water heaters |
| Fuel | Propane |
| Stated mounting location | Outdoor |
| Stated maximum flow | 6.6 GPM |
| Stated gas input | 140,000 BTU/h |
| Buyer reviews | 5 · 4.0/5 |
| ASIN | B00MBBH1YY |
Full listing title: Noritz NR66ODLP Outdoor Tankless Water Heater, max. 140,000 Btuh, 6.6 Gpm - Liquid Propane
| Fuel | Liquid PropaneFull listing title |
|---|---|
| Stated mounting location | OutdoorFull listing title |
| Stated maximum flow | 6.6 GpmFull listing title |
| Stated gas input | 140,000 BtuhFull listing title |
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. Up north in winter, 42 °F water has to climb 63 °F to reach a 105 °F shower, and the flow drops with it. Ask for the flow chart and read that line. 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.
What it has going for it
Mounts outside. No vent pipe through the roof or the rim joist: it hangs on an outside wall and breathes on its own. In a cold climate, ask what keeps it from freezing.
Mild winters: hang it outside and you skip the vent run through the rim joist and the combustion-air questions indoors.
Hard freezes: the listing names no freeze protection, so ask the seller what keeps it from bursting before it goes on a north wall.
What the Noritz NR66ODLP Outdoor Propane listing names:
Read the installation manual for the vent, the gas line size and the clearances before you order; it overrides anything above.
At the price on Sep 30, 2026, each GPM of stated maximum flow works out at about $171.26 (price ÷ stated GPM, our arithmetic). That puts it in the pricier third of the 32 outdoor tankless heaters we have a price and a stated flow for.
Outside mounting saves the vent pipe; the gas line, the water lines and a weatherproof outlet are still a separate bill.
The button opens the exact listing (ASIN B00MBBH1YY), where today's price, stock and seller apply.
Two showers and the dishwasher at once? The A. O. Smith 10 GPM Natural Gas Outdoor (8.0/10) states up to 10 GPM.
Hard freezes where you live? The Marey 170,000 BTU Propane Indoor (7.6/10) is an indoor unit, out of the frost.
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
What we'd buy the Noritz NR66ODLP Outdoor Propane for is a 6.6 GPM maximum flow, with outdoor mounting that skips the flue as a bonus. Only 5 buyers have rated it so far (4.0/5), so treat the score as an early read. Where it falls short: their 4.0/5 average sits under the 4.3 of our ranked picks. We'd pick it if you run one shower and the kitchen tap at once, rarely more; otherwise, put it next to the Noritz NR50ODLP Outdoor Propane first.
It goes on an outside wall, with gas, water and power run to it. Plan the gas line for 140,000 BTU/h; 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 clear leaves and wasp nests from the cabinet vents. Our flushing and descaling guide has the checklist.
Buyers give it 4.0/5, a decent record, below our ranked picks' 4.3 average. Only 5 reviews so far, and our formula damps averages built on fewer than 50.
Before you order the Noritz NR66ODLP Outdoor Propane, check your gas line: 140,000 BTU/h is a lot of gas at once, so ask your plumber whether the existing line can feed it.
6.6 GPM is the headline. In a northern January the water comes in near 42 °F, so a 105 °F shower needs a 63 °F rise and the real flow drops. Our flow-rate calculator runs the numbers for your house.
Pick a wall away from windows and doors, with power for the controls. Our indoor vs outdoor guide compares the two installs.
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 Noritz NR66ODLP Outdoor Propane stacks up against the closest alternative, the Noritz NR50ODLP Outdoor Propane.
| Criterion | Noritz NR66ODLP Outdoor Propane | Noritz NR50ODLP Outdoor Propane |
|---|---|---|
| Our rating | 6.2/10 | 6.2/10 |
| Max flow | 6.6 GPM | 5 GPM |
| Gas input | 140,000 BTU/h | 120,000 BTU/h |
| Buyer reviews | 5 · 4.0/5 | 11 · 4.8/5 |
Both score 6.2/10. The Noritz NR50ODLP Outdoor Propane adds a higher buyer rating (4.8/5), while the Noritz NR66ODLP Outdoor Propane brings more flow (6.6 GPM) and a bigger burner (140,000 BTU/h).
We rate it 6.2/10 (fair). The rating comes from its documented listing alone, as no customer-review record is captured yet.
The listing states a maximum flow of 6.6 GPM and a gas input of 140,000 BTU/h. 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.
The listing says outdoor mounting. It only goes inside if the maker lists that exact model for indoor use, with the venting it specifies; a licensed gas installer confirms the spot under your local code.
Its listing states up to 6.6 GPM and outdoor mounting that skips the flue. 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: 6.6 GPM is the headline. In a northern January the water comes in near 42 °F, so a 105 °F shower needs a 63 °F rise and the real flow drops. Our flow-rate calculator runs the numbers for your house. The outside wall: pick a wall away from windows and doors, with power for the controls. Our indoor vs outdoor guide compares the two installs. The warranty terms: 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 and 5 buyer reviews, read line by line and weighed with our published formula.