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Ranein Condensing Propane, 5.1 GPM Review

Written from the listing's specs, not from our own use · How we rate

If you're after a 5.1 GPM maximum flow, the Ranein Condensing Propane (5.1 GPM) delivers, with condensing efficiency and a ±1 °F temperature hold on top. It makes most sense for a cabin, a garage apartment or an in-law suite; we rate it 7.4/10 from its listing.

Price$559Price on Sep 30, 2026 · may have changed
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Specifications
BrandRanein
CategoryGas tankless water heaters
FuelPropane
Stated maximum flow5.1 GPM
Stated gas input120,000 BTU/h
Stated voltage120 V
Condensing designStated in the listing title
Temperature range95 to 149 °F
Temperature hold±1 °F, per the listing
Freeze protectionStated in the listing
ASINB0GZVV4KXN

Full listing title: Ranein Condensing Propane Tankless Water Heater, 5.1 GPM, 120,000 BTU

Listing evidence
FuelPropane Full listing title
Stated maximum flow5.1 GPM Full listing title
Stated gas input120,000 BTU Full listing title
Stated voltage120V Listing text
Condensing designCondensing Full listing title
Updated October 2026
Exact listing, ASIN B0GZVV4KXN
Rating from a published formula

Compared with its closest rivals

Two gas tankless heaters on propane too, with about the same flow, closest to it on our rating, each with a dated price.

Compare side by side ↗

Ranein Condensing Propane, 5.1 GPM

Ranein Condensing Propane, 5.1 GPM

7.4Good · out of 10$559 Price on Sep 30, 2026 · may have changed
  • Stated: 5.1 GPM · 120,000 BTU/h · 120 V
  • Gas tankless water heaters
This product ↑
MIZUDO 120,000 BTU Propane

MIZUDO 120,000 BTU Propane

7.6Very good · out of 10$539.99 Price on Sep 30, 2026 · may have changed
  • Stated: 5.1 GPM · 120,000 BTU/h
  • Gas tankless water heaters
See the review ↗
ThermoMate Condensing Propane

ThermoMate Condensing Propane

7.6Very good · out of 10$559.99 Price on Sep 30, 2026 · may have changed
  • Stated: 5.28 GPM · 114,000 BTU/h · 120 V
  • Gas tankless water heaters
See the review ↗

Up to 5.1 GPM from a 120,000 BTU burner

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. Counting 2 GPM per shower, as our calculator does, that's one shower and a sink at a time, maybe two showers where the water comes in warm.

What it has going for it

What changes in the morning shower rush

Condensing. A second heat exchanger pulls heat out of the exhaust before it leaves, so more of the gas you pay for ends up in the water. The exhaust runs cool enough for plastic vent pipe, and the condensate needs a drain.

±1 °F hold. The burner adjusts as the flow changes, so the shower stays where you set it when somebody opens the kitchen tap. On paper, at least: that is the seller's claim.

Natural gas or propane?

Propane: that's what the listing names. A propane unit runs off a tank outside, so the tank size and the regulator are part of the plan.

Natural gas: it's a different set of gas jets and pressures. Only the maker's conversion kit, if there is one, and a licensed gas fitter can switch it; ask before you order.

Great for you if…

  • You care about the gas bill as much as the hot water
  • A shower that suddenly runs cold drives you mad
  • It will live in a garage, a cabin or another cold spot

Skip it if…

  • You'd rather wait for buyer reviews: none are captured for this listing yet
  • The far bathroom already waits a minute for hot water: no built-in recirculation is named
  • You want the warranty terms in writing: the listing gives no number of years

What Ranein promises

The seller states, word for word, in the Ranein Condensing Propane (5.1 GPM) listing:

  • Set temperature from 95°F to 149°F at ±1°F precision via the LED touchscreen.
  • An integrated 114W anti-freeze heater activates automatically below 42.8°F to protect internal components in cold winters.
  • Standard 3/4" NPT connections and 120V plug-in power.

The seller's claims, quoted as written; we haven't measured any of it. The flow at your winter rise is in the maker's chart, not in the bullet points.

Ranein Condensing Propane, 5.1 GPM, view 3

Gas, venting and what's in the box

What the Ranein Condensing Propane (5.1 GPM) listing names:

  • Up to 5.1 GPM
  • 120,000 BTU/h input
  • Propane
  • Condensing
  • 120 V plug for the controls
  • ±1 °F temperature hold claimed
  • 95 to 149 °F setpoint
  • Freeze protection named

For the Ranein Condensing Propane (5.1 GPM), the installation manual settles the venting, the gas line and the clearances.

Ranein Condensing Propane, 5.1 GPM, view 4

Price and cost per GPM of stated flow

$559 Price on Sep 30, 2026 · may have changed

At the price on Sep 30, 2026, each GPM of stated maximum flow works out at about $109.61 (price ÷ stated GPM, our arithmetic). That puts it in the pricier third of the 10 gas tankless heaters we have a price and a stated flow for.

Count the install in the budget: vent pipe, possibly a 3/4" gas line, and a licensed plumber or gas fitter.

The button opens the exact listing (ASIN B0GZVV4KXN), where today's price, stock and seller apply.

Ranein Condensing Propane, 5.1 GPM, view 5

A better fit for your house?

Two showers and the dishwasher at once? The Rheem RTG 8.4 GPM Propane Outdoor (7.5/10) states up to 8.4 GPM.

On natural gas, not propane? The ThermoMate Condensing Natural Gas (7.7/10) runs on natural gas.

Our take

The verdict

What we'd buy the Ranein Condensing Propane (5.1 GPM) for is a 5.1 GPM maximum flow, with condensing efficiency as a bonus. No buyer reviews yet, so this Ranein gas tankless heater has to win you over on paper. The catch with the Ranein: no word on the warranty. We'd pick it if you care about the gas bill as much as the hot water; otherwise, put it next to the GASLAND BE158B Propane (1.58 GPM) first.

Living with it

Install day

Old tank out, unit on the wall, vent through the wall or the roof. Plan the gas line for 120,000 BTU/h; a licensed pro handles it, and often a permit.

The first shower

Hot water arrives after the cold already in the pipes, then stays (within ±1 °F, per the listing). A trickle from a bathroom tap may not light the burner; open it a bit more.

The first winter

January water comes in colder, so the same unit gives fewer GPM. Stagger the showers if you sized it tight.

Once a year

Flush the heat exchanger with a pump and a descaler (the service valves make it an hour's job), check the condensate drain and the neutralizer, and clean the inlet filter. Our flushing and descaling guide has the checklist.

The one thing we'd check first

Before the Ranein Condensing Propane (5.1 GPM) ships, check your gas line: 120,000 BTU/h is a lot of gas at once, so ask your plumber whether the existing line can feed it.

Before you buy

Your winter flow

5.1 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.

Vent and gas line

Ask the plumber to check the gas line size and the meter against the heater's input, and to quote the vent route at the same visit. Our install cost guide shows what that usually adds.

The condensate

A condensing unit drips acidic water that needs a drain, often through a neutralizer. Our condensing guide explains the extra parts.

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.

How it compares

How the Ranein Condensing Propane (5.1 GPM) stacks up against the closest alternative, the GASLAND BE158B Propane (1.58 GPM).

CriterionRanein Condensing Propane, 5.1 GPMGASLAND BE158B Propane, 1.58 GPM
Our rating7.4/107.4/10
Max flow5.1 GPM1.58 GPM
Gas input120,000 BTU/hNot stated
EfficiencyCondensingNot stated
Temperature hold±1 °F statedNot stated

Both score 7.4/10. The Ranein Condensing Propane (5.1 GPM) brings more flow (5.1 GPM) and a bigger burner (120,000 BTU/h), so it has the edge on paper.

The score in detail

How we rated it

Spec-based rating on a 4.5–8.5 scale: 4.5 + average of the 4 criteria × 0.4. Capped at 8.5 because no customer evidence is included.

Key specifications

9 / 10

Build, warranty & certifications

4 / 10

Listing documentation

8 / 10

Fit & compatibility

8 / 10

This product has no captured buyer-review record yet, so its rating comes from the documented listing alone: four criteria scored out of 10 (key specifications; build, warranty and certifications; listing documentation; fit and compatibility), placed on a 4.5–8.5 scale. Read the full methodology.

Read the methodology →

Frequently asked questions

Is the Ranein Condensing Propane (5.1 GPM) any good?

We rate it 7.4/10 (good). The rating comes from its documented listing alone, as no customer-review record is captured yet.

How much hot water can the Ranein Condensing Propane, 5.1 GPM deliver?

The listing states a maximum flow of 5.1 GPM and a gas input of 120,000 BTU/h on 120 V. 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.

What do you get with the Ranein Condensing Propane (5.1 GPM)?

Its listing states up to 5.1 GPM, a condensing heat exchanger, temperature held within ±1 °F and freeze protection. 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.

What should I check before ordering the Ranein Condensing Propane (5.1 GPM)?

Your winter flow: 5.1 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. Vent and gas line: ask the plumber to check the gas line size and the meter against the heater's input, and to quote the vent route at the same visit. Our install cost guide shows what that usually adds. The condensate: a condensing unit drips acidic water that needs a drain, often through a neutralizer. Our condensing guide explains the extra parts. 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.

Where can I buy the Ranein Condensing Propane (5.1 GPM)?

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.

Have you used the Ranein Condensing Propane (5.1 GPM) yourselves?

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.