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Novieex 100,000 BTU Natural Gas Indoor Review

Name: Novieex 100,000 BTU Natural Gas Indoor
Brand: Novieex
SKU: B0FN7ZH4JF

5.7Fair · out of 10Not in our top-5 rankings

Written from the listing and 45 buyer reviews, not from our own use · How we rate

The Novieex 100,000 BTU Natural Gas Indoor packs up to 4.3 GPM and temperature held within ±1 °F into one indoor gas tankless heater. 45 buyers rate it 4.0/5, and it suits one shower at a time and not much more.

Price$269.97Price on Sep 30, 2026 · may have changed

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

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Specifications

Brand	Novieex
Category	Gas tankless water heaters
Fuel	Natural gas
Stated mounting location	Indoor
Stated maximum flow	4.3 GPM
Stated gas input	100,000 BTU/h
Stated voltage	110 V
Temperature range	95 to 149 °F
Temperature hold	±1 °F, per the listing
Water pressure	From 1.5 PSI
Stated warranty	1 years
Buyer reviews	45 · 4.0/5
ASIN	B0FN7ZH4JF

Full listing title: Novieex Natural Gas Tankless Water Heater Up to 4.3 GPM 100,000 BTU, Indoor

Listing evidence

Fuel	Natural Gas Full listing title
Stated mounting location	Indoor Full listing title
Stated maximum flow	4.3 GPM Full listing title
Stated gas input	100,000 BTU Full listing title
Stated voltage	110V Listing text

Updated October 2026

Exact listing, ASIN B0FN7ZH4JF

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 ↗

Novieex 100,000 BTU Natural Gas Indoor

5.7Fair · out of 10$269.97 Price on Sep 30, 2026 · may have changed

Stated: 4.3 GPM · 100,000 BTU/h · 110 V
45 buyer reviews
Gas tankless water heaters

This product ↑

APUS 80,000 BTU Natural Gas Indoor

6.7Good · out of 10$249.99 Price on Sep 30, 2026 · may have changed

Stated: 3.6 GPM · 80,000 BTU/h · 120 V
141 buyer reviews
Gas tankless water heaters

See the review ↗

ThermoMate CZ422NG Natural Gas Indoor

6.8Good · out of 10$399.99 Price on Sep 30, 2026 · may have changed

Stated: 5 GPM · 113,000 BTU/h · 120 V
161 buyer reviews
Gas tankless water heaters

See the review ↗

Up to 4.3 GPM from a 100,000 BTU burner

That's the maximum flow the listing states, and headline flows are usually quoted at a mild temperature 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. At 2 GPM a shower (our calculator's figure), the headline means one shower at a time.

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.

95 to 149 °F. The setpoint range per the listing. Above 120 °F at the tap is scalding territory for kids, so most homes set it lower.

One shower at a time, or two?

One at a time: that's what 4.3 GPM is for.

Two at once: not with this one. Look at the bigger units further down this page.

Great for you if…

A shower that suddenly runs cold drives you mad

Skip it if…

Two showers often run at once in your house: 4.3 GPM is a one-shower unit
You want a long review record: only 45 buyer reviews so far
Star ratings come first for you: 4.0/5 is below the 4.3 average of our ranked picks

Gas, venting and what's in the box

What the Novieex 100,000 BTU Natural Gas Indoor listing names:

Up to 4.3 GPM
100,000 BTU/h input
Natural gas
Indoor mounting
Starts from 1.5 PSI
±1 °F temperature hold claimed
95 to 149 °F setpoint

Warranty & support: 1-year warranty, as stated in the listing.

That is the maker's promise, not ours. Keep the invoice, register the Novieex 100,000 BTU Natural Gas Indoor if the maker asks, and read the install conditions: many tankless warranties need a licensed install and regular flushing.

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

Novieex 100,000 BTU Natural Gas Indoor, view 3

Price and cost per GPM of stated flow

$269.97 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 $62.78 (price ÷ stated GPM, our arithmetic). That puts it in the cheaper third of the 45 indoor gas tankless heaters we have a price and a stated flow for.

The heater is often the smaller half of the bill: the venting, a gas line that may need upsizing and a licensed installer's day come on top.

The button opens the exact listing (ASIN B0FN7ZH4JF), where today's price, stock and seller apply.

Novieex 100,000 BTU Natural Gas Indoor, view 4

A better fit for your house?

Two showers and the dishwasher at once? The Ranein 190,000 BTU Natural Gas Indoor (7.9/10) states up to 8.5 GPM.

Want the high-efficiency kind? The Ranein Condensing Natural Gas, 5.1 GPM (7.4/10) is a condensing unit, per its listing.

On propane, not natural gas? The ThermoMate CZ422LP Propane Indoor (7.8/10) runs on propane.

Our take

The verdict

We like the Novieex 100,000 BTU Natural Gas Indoor for up to 4.3 GPM and temperature held within ±1 °F. Only 45 buyers have rated it so far (4.0/5), so treat the score as an early read. The catch with this Novieex indoor gas tankless heater: their 4.0/5 average sits under the 4.3 of our ranked picks. We'd pick it if a shower that suddenly runs cold drives you mad; otherwise, put it next to the Rinnai RUCS65IN Natural Gas first.

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 100,000 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), and clean the inlet filter. Our flushing and descaling guide has the checklist.

What buyers say

Buyers give it 4.0/5, a decent record, below our ranked picks' 4.3 average. Only 45 reviews so far, and our formula damps averages built on fewer than 50.

The numbers

Buyer rating: 4.0/5
Reviews: 45
Ranked picks' average: 4.3/5

The one thing we'd check first

Before the Novieex 100,000 BTU Natural Gas Indoor ships, check your gas line: 100,000 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

4.3 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 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.

How it compares

How the Novieex 100,000 BTU Natural Gas Indoor stacks up against the closest alternative, the Rinnai RUCS65IN Natural Gas.

Criterion	Novieex 100,000 BTU Natural Gas Indoor	Rinnai RUCS65IN Natural Gas
Our rating	5.7/10	6.0/10
Max flow	4.3 GPM	6.5 GPM
Gas input	100,000 BTU/h	Not stated
Temperature hold	±1 °F stated	Not stated
Buyer reviews	45 · 4.0/5	62 · 4.0/5

Pick the Rinnai RUCS65IN Natural Gas if you want our higher-rated option (6.0/10), with more flow (6.5 GPM); stay with the Novieex 100,000 BTU Natural Gas Indoor for a bigger burner (100,000 BTU/h) and a stated ±1 °F hold.

Compare side by side ↗See the Rinnai RUCS65IN Natural Gas review →

The score in detail

How we rated it

Our score: 5.7/10

Buyer rating (45%)

32.4 / 45

4.0/5 average, confidence-damped (45 reviews < 50)

Review volume (35%)

15.7 / 35

45 buyer reviews

Documented specifications (20%)

8.6 / 20

43/100 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 for this exact listing, 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 Novieex 100,000 BTU Natural Gas Indoor any good?

We rate it 5.7/10 (fair). It is based on 45 buyer reviews averaging 4.0/5 and the specifications stated in the listing.

How much hot water can the Novieex 100,000 BTU Natural Gas Indoor deliver?

The listing states a maximum flow of 4.3 GPM and a gas input of 100,000 BTU/h on 110 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.

Can the Novieex 100,000 BTU 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 Novieex 100,000 BTU Natural Gas Indoor?

Its listing states up to 4.3 GPM and temperature held within ±1 °F. 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 Novieex 100,000 BTU Natural Gas Indoor?

Your winter flow: 4.3 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 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.

Where can I buy the Novieex 100,000 BTU 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 Novieex 100,000 BTU Natural Gas Indoor yourselves?

No, we haven't used it ourselves. Everything on this page comes from its listing and 45 buyer reviews, read line by line and weighed with our published formula.

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