Product images: Amazon listings

Rheem RTG 7.0 GPM Natural Gas Indoor Review

Name: Rheem RTG 7.0 GPM Natural Gas Indoor
Brand: Rheem
SKU: B0C827XPJ5

7.0Good · out of 10Not in our top-5 rankings

Written from the listing and 65 buyer reviews, not from our own use · How we rate

We like the Rheem RTG 7.0 GPM Natural Gas Indoor for the mix: up to 7 GPM, temperature held within ±1 °F and built-in freeze protection. It suits one shower plus the kitchen in a typical family morning, and its sibling listing, the Rheem RTG 9.5 GPM Natural Gas Indoor, holds #5 in our indoor natural gas tankless water heater ranking.

Variants of this model

These are sold as variants of one listing family. Each variant has its own page.

Rheem RTG 9.5 GPM Natural Gas Indoor · 9.5 GPM (Standard) / Gray · 7.2/10

Price$653.77Price on Sep 30, 2026 · may have changed

Check the price on Amazon ↗Affiliate link · price and stock on Amazon

Compare side by side ↗

Specifications

Brand	Rheem
Category	Gas tankless water heaters
Fuel	Natural gas
Stated mounting location	Indoor
Stated maximum flow	7 GPM
Stated gas input	160,000 BTU/h
Flow at a stated rise	7 GPM at a 35 °F rise
Temperature hold	±1 °F, per the listing
Freeze protection	Stated in the listing
Buyer reviews	65 · 4.5/5
ASIN	B0C827XPJ5

Full listing title: Rheem RTG Series 7.0 GPM Natural Gas Tankless Water Heater Indoor | 160,000 BTUs High Efficiency On Demand, Continuous Hot Water | Non-Condensing

Listing evidence

Fuel	Natural Gas Full listing title
Stated mounting location	Indoor Full listing title
Stated maximum flow	7.0 GPM Full listing title
Stated gas input	160,000 BTUs Full listing title

Updated October 2026

Exact listing, ASIN B0C827XPJ5

Rating from a published formula

Compared with its closest rivals

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

Compare side by side ↗

Rheem RTG 7.0 GPM Natural Gas Indoor

7.0Good · out of 10$653.77 Price on Sep 30, 2026 · may have changed

Stated: 7 GPM · 160,000 BTU/h
65 buyer reviews
Gas tankless water heaters

This product ↑

Eccotemp SMARTHOME Natural Gas, 6.8 GPM

7.1Good · out of 10$699 Price on Sep 30, 2026 · may have changed

Stated: 6.8 GPM · 140,000 BTU/h
3 buyer reviews
Gas tankless water heaters

See the review ↗

Rinnai RE180iN Non-Condensing

7.1Good · out of 10$1,091.16 Price on Sep 30, 2026 · may have changed

Stated: 6.9 GPM
16 buyer reviews
Gas tankless water heaters

See the review ↗

Up to 7 GPM from a 160,000 BTU burner

That's the maximum flow the listing states, at a 35 °F rise. A cold January asks for a 63 °F rise (42 °F in, 105 °F out), and at that rise every tankless gives less than its headline; the maker's chart says how much. Our calculator counts a shower at 2 GPM, so on paper that's two showers and a kitchen tap, less when the water comes in cold.

What it has going for it

What changes in the morning shower rush

±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.

Freeze protection. Stated in the listing. Useful in a garage, a crawl space or a cabin that sits empty in winter, as long as the unit keeps power.

One shower at a time, or two?

One at a time, plus the kitchen tap: 7 GPM covers that on paper. The listing gives 7 GPM at a 35 °F rise and the seller says it serves up to 2 showers.

Two at once: it depends on your groundwater. With 42 °F water in January, expect the second shower to cool off; the flow chart at a 63 °F rise tells you by how much.

Great for you if…

You run one shower and the kitchen tap at once, rarely more
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 want the high-efficiency kind: the listing doesn't call it condensing
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

Gas, venting and what's in the box

What the Rheem RTG 7.0 GPM Natural Gas Indoor listing names:

Up to 7 GPM
7 GPM at a 35 °F rise
160,000 BTU/h input
Natural gas
Indoor mounting
±1 °F temperature hold claimed
Freeze protection named
CSA, ETL or UL mark named

The installation manual has the last word on venting, gas line and clearances; your installer reads it before you order.

Rheem RTG 7.0 GPM Natural Gas Indoor, view 3

Price and cost per GPM of stated flow

$653.77 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 $93.40 (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 B0C827XPJ5), where today's price, stock and seller apply. Sizes and variants of the same family often sit at different prices.

Rheem RTG 7.0 GPM Natural Gas Indoor, view 4

A better fit for your house?

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 Rheem RTG 7.0 GPM Natural Gas Outdoor (7.6/10) mounts on an outside wall, per its listing.

On propane, not natural gas? The Marey 170,000 BTU Propane Indoor (7.6/10) runs on propane.

Our take

The verdict

We like the Rheem RTG 7.0 GPM Natural Gas Indoor for up to 7 GPM and temperature held within ±1 °F. Only 65 buyers have rated it so far (4.5/5), so treat the score as an early read. The catch with this Rheem indoor gas tankless heater: no word on the warranty. Before you decide, put it next to the Eccotemp SMARTHOME Natural Gas (6.8 GPM).

Check the price on Amazon ↗Affiliate link · price and stock on AmazonAll gas tankless water heaters →

Living with it

Install day

Old tank out, unit on the wall, vent through the wall or the roof. Plan the gas line for 160,000 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. The listing's 7 GPM is at a 35 °F rise; a northern winter asks for about 63 °F. 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), and clean the inlet filter. Our flushing and descaling guide has the checklist.

What buyers say

Buyers give it 4.5/5, a strong record, above our ranked picks' 4.3 average. 65 reviews is still a modest pile, so a handful of new ones can move it.

The numbers

Buyer rating: 4.5/5
Reviews: 65
Ranked picks' average: 4.3/5

The one thing we'd check first

Before the Rheem RTG 7.0 GPM Natural Gas Indoor goes in your cart, check your winter rise: it is rated 7 GPM at a 35 °F rise, and a northern winter asks for nearer 63 °F.

Before you buy

Your winter flow

Find your winter inlet temperature (your water utility or a thermometer at the cold tap in January), subtract it from 105 °F, and read the maker's flow chart at that rise. 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 160,000 BTU/h. Get that quote before you order; our installation guide lists what they will ask.

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.

How it compares

How the Rheem RTG 7.0 GPM Natural Gas Indoor stacks up against the closest alternative, the Eccotemp SMARTHOME Natural Gas (6.8 GPM).

Criterion	Rheem RTG 7.0 GPM Natural Gas Indoor	Eccotemp SMARTHOME Natural Gas, 6.8 GPM
Our rating	7.0/10	7.1/10
Max flow	7 GPM	6.8 GPM
Gas input	160,000 BTU/h	140,000 BTU/h
Temperature hold	±1 °F stated	Not stated
Warranty	Not stated	5 years (heat exchanger)
Buyer reviews	65 · 4.5/5	3 · 2.7/5

Pick the Eccotemp SMARTHOME Natural Gas (6.8 GPM) if you want our higher-rated option (7.1/10), with a longer stated warranty (5 years); stay with the Rheem RTG 7.0 GPM Natural Gas Indoor for more flow (7 GPM) and a bigger burner (160,000 BTU/h).

Compare side by side ↗See the Eccotemp SMARTHOME Natural Gas, 6.8 GPM review →

The score in detail

How we rated it

Our score: 7.0/10

Buyer rating (45%)

40.5 / 45

4.5/5 average

Review volume (35%)

17.2 / 35

65 buyer reviews

Documented specifications (20%)

12.6 / 20

63/100 listing documentation score

Our rating is an evidence index on a 0–10 scale. It is not a buyer star rating, and we have not used the product ourselves.

Buyer rating (45%): the captured average shown on this variant's own listing page (not shared with the other Rheem RTG variants), damped when there are fewer than 50 reviews.
Review volume (35%): more reviews mean more reliable evidence, on a logarithmic scale up to 5,000 reviews.
Documented specifications (20%): how completely the exact listing documents the attributes that matter.

Our editors then look at how it compares with the other heaters we rate. A commission is never an input to the rating. Read the full methodology.

Read the methodology →

Frequently asked questions

Is the Rheem RTG 7.0 GPM Natural Gas Indoor any good?

We rate it 7.0/10 (good). It is based on 65 buyer reviews averaging 4.5/5 and the specifications stated in the listing.

How much hot water can the Rheem RTG 7.0 GPM Natural Gas Indoor deliver?

The listing states a maximum flow of 7 GPM and a gas input of 160,000 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.

Can the Rheem RTG 7.0 GPM Natural Gas Indoor be installed indoors?

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.

What do you get with the Rheem RTG 7.0 GPM Natural Gas Indoor?

Its listing states up to 7 GPM, 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 Rheem RTG 7.0 GPM Natural Gas Indoor?

Your winter flow: find your winter inlet temperature (your water utility or a thermometer at the cold tap in January), subtract it from 105 °F, and read the maker's flow chart at that rise. 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 160,000 BTU/h. Get that quote before you order; our installation guide lists what they will ask. 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.

Where can I buy the Rheem RTG 7.0 GPM Natural Gas Indoor?

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 Rheem RTG 7.0 GPM Natural Gas Indoor yourselves?

No, we haven't used it ourselves. Everything on this page comes from its listing and 65 buyer reviews, read line by line and weighed with our published formula.

Gas tankless water heaters ↗All Rheem products Comparison tool All product reviews