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Westinghouse 18 kW Electric, 240V Review

Name: Westinghouse 18 kW Electric, 240V
Brand: Westinghouse
SKU: B0GKFM8KS3

5.4Fair · out of 10Not in our top-5 rankings

Written from the listing and 37 buyer reviews, not from our own use · How we rate

On paper, the Westinghouse 18 kW Electric (240V) gets the important things right: 18 kW at 240 V and Wi-Fi control from your phone. It suits a southern house with warm tap water and no gas line, at 5.4/10 on our rating.

Price$407.99Price 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	Westinghouse
Category	Electric tankless water heaters
Fuel	Electric
Stated heating power	18 kW
Stated voltage	240 V
Flow by inlet temperature	4.2 GPM at 77 °F inlet, 2.6 GPM at 57 °F inlet
Minimum activation flow	0.5 GPM
Total current	75 A
Wi-Fi	Built in, per the listing
Buyer reviews	37 · 4.2/5
ASIN	B0GKFM8KS3

Full listing title: Westinghouse Tankless Water Heater Electric 18kW 240V Wifi Whole House Use

Listing evidence

Fuel	Electric Full listing title
Stated heating power	18kW Full listing title
Stated voltage	240V Full listing title

Updated October 2026

Exact listing, ASIN B0GKFM8KS3

Rating from a published formula

Compared with its closest rivals

Two electric tankless heaters of about the same power, closest to it on our rating, each with a dated price.

Compare side by side ↗

Westinghouse 18 kW Electric, 240V

5.4Fair · out of 10$407.99 Price on Sep 30, 2026 · may have changed

Stated: 18 kW · 240 V
37 buyer reviews
Electric tankless water heaters

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Bosch Tronic 6100, 18 kW

6.5Good · out of 10$629 Price on Sep 30, 2026 · may have changed

Stated: 18 kW
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Vancepic 18 kW Electric, 240V

6.8Good · out of 10$329 Price on Sep 30, 2026 · may have changed

Stated: 18 kW · 240 V
19 buyer reviews
Electric tankless water heaters

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18 kW at 240 V

The heating power the listing states. At 240 V it draws about 75 A. Show that to your electrician first. Whether your panel has the room is the whole question, and the shower comes second.

What it has going for it

What changes in the morning shower rush

Wi-Fi app. Set the temperature, see the flow and get error codes on your phone, which beats reading a blinking code in the crawl space.

Starts at 0.5 GPM. The minimum flow that switches it on. A low-flow bathroom tap opened gently may not trigger it, which is worth knowing before it goes under the sink.

Warm tap water or a cold January?

Warm tap water: where it comes in around 62 °F (much of the South), 18 kW gives about 2.9 GPM of 105 °F water on our calculator's maths. That's one 2 GPM shower at a time.

A cold January: where it comes in at 42 °F, it's about 1.9 GPM, less than one 2 GPM shower. Up north, that's the figure to size against, and it's why the honest answer is sometimes a second unit or gas.

Great for you if…

You live somewhere the tap water never gets icy
You like to see what your appliances are doing

Skip it if…

You want self-modulating power: the listing doesn't say it modulates
You want a long review record: only 37 buyer reviews so far
Your panel is already close to full: 18 kW is about 75 A at 240 V

Power, wiring and what's in the box

What the Westinghouse 18 kW Electric (240V) listing names:

18 kW
240 V
75 A total draw
Switches on at 0.5 GPM
Digital display
Wi-Fi app control
CSA, ETL or UL mark named

The installation manual has the last word on breakers and wire size; show it to your electrician before you order.

Westinghouse 18 kW Electric, 240V, view 3

Price and cost per kW

$407.99 Price on Sep 30, 2026 · may have changed

At the price on Sep 30, 2026, each kW of stated heating power works out at about $22.67 (price ÷ stated kW, our arithmetic). That puts it in the pricier third of the 27 whole-house electric tankless heaters we have a price and a stated power for.

The electrician comes on top: new double-pole breakers, heavy wire and, in some houses, a panel upgrade.

The button opens the exact listing (ASIN B0GKFM8KS3), where today's price, stock and seller apply.

Westinghouse 18 kW Electric, 240V, view 4

A better fit for your house and panel?

Colder tap water where you live? The WINTEMP WN-36kW Electric, 240V (8.1/10) is rated 36 kW.

Only one sink far from the heater? The ThermoMate 14 kW Electric, 240V (7.9/10) is a 14 kW point-of-use unit.

Want it to draw only what it needs? The Rheem 18 kW Electric, 240V (9.3/10) is self-modulating, per its listing.

Our take

The verdict

Our favourite thing about the Westinghouse 18 kW Electric (240V) is 18 kW at 240 V, closely followed by Wi-Fi control from your phone. Only 37 buyers have rated it so far (4.2/5), so treat the score as an early read. The catch with this Westinghouse electric tankless heater: no stated self-modulation, while most picks here have it. We'd pick it if you live somewhere the tap water never gets icy; otherwise, put it next to the Eemax EEM24036 (36 kW) first.

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

Living with it

Install day

New breakers, the unit on the wall next to the old tank's spot, water in and out. An electrician does the panel side.

The first shower

Hot in a few seconds once the water in the pipes has passed. Set it, then leave it.

The first winter

With 42 °F water coming in, 18 kW gives about 1.9 GPM at 105 °F on our calculator's maths. Low-flow shower heads stretch that further.

Upkeep

Clean the inlet screen and flush out scale on hard water. Our flushing and descaling guide has the routine.

What buyers say

Buyers give it 4.2/5, a solid record, slightly below our ranked picks' 4.3 average. Only 37 reviews so far, and our formula damps averages built on fewer than 50.

The numbers

Buyer rating: 4.2/5
Reviews: 37
Ranked picks' average: 4.3/5

The one thing we'd check first

Before you order the Westinghouse 18 kW Electric (240V), check your panel: it draws 75 A, so an electrician should look at the panel first.

Before you buy

Your panel

Take a photo of the panel label (main breaker size and free slots) and send it to the electrician with the listing. Our electrical requirements guide explains what they will look for.

Your winter flow

On our calculator's maths, 18 kW gives about 1.9 GPM with 42 °F winter water and 2.9 GPM with 62 °F water. Our flow-rate calculator does it for your region.

The install

Hardwired 240 V work needs a licensed electrician and often a permit. Our install cost guide shows what usually ends up on the quote.

Scale

Hard water still builds up on the elements and the inlet screen. Our flushing and descaling guide covers the routine.

How it compares

How the Westinghouse 18 kW Electric (240V) stacks up against the closest alternative, the Eemax EEM24036 (36 kW).

Criterion	Westinghouse 18 kW Electric, 240V	Eemax EEM24036, 36 kW
Our rating	5.4/10	5.6/10
Heating power	18 kW	36 kW
Voltage	240 V	Not stated
Breakers	75 A total	Not stated
Self-modulating	Not stated	Stated
Buyer reviews	37 · 4.2/5	None captured

Pick the Eemax EEM24036 (36 kW) if you want our higher-rated option (5.6/10), with more power (36 kW) and self-modulating power.

Compare side by side ↗See the Eemax EEM24036, 36 kW review →

The score in detail

How we rated it

Our score: 5.4/10

Buyer rating (45%)

28.0 / 45

4.2/5 average, confidence-damped (37 reviews < 50)

Review volume (35%)

14.9 / 35

37 buyer reviews

Documented specifications (20%)

10.6 / 20

53/100 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 Westinghouse 18 kW Electric (240V) any good?

We rate it 5.4/10 (fair). It is based on 37 buyer reviews averaging 4.2/5 and the specifications stated in the listing.

How much hot water can the Westinghouse 18 kW Electric, 240V deliver?

The listing states a heating power of 18 kW on 240 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 electrical service does the Westinghouse 18 kW Electric, 240V need?

The listing states 240 V and 18 kW. At 240 V, that is roughly 75 A. A licensed electrician checks the panel, the breakers and the wiring before it goes on the wall.

What do you get with the Westinghouse 18 kW Electric (240V)?

Its listing states 18 kW of heating power and Wi-Fi control from your phone. 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 Westinghouse 18 kW Electric (240V)?

Your panel: take a photo of the panel label (main breaker size and free slots) and send it to the electrician with the listing. Our electrical requirements guide explains what they will look for. Your winter flow: on our calculator's maths, 18 kW gives about 1.9 GPM with 42 °F winter water and 2.9 GPM with 62 °F water. Our flow-rate calculator does it for your region. The install: hardwired 240 V work needs a licensed electrician and often a permit. Our install cost guide shows what usually ends up on the quote. Scale: hard water still builds up on the elements and the inlet screen. Our flushing and descaling guide covers the routine.

Where can I buy the Westinghouse 18 kW Electric (240V)?

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 Westinghouse 18 kW Electric (240V) yourselves?

No, we haven't used it ourselves. Everything on this page comes from its listing and 37 buyer reviews, read line by line and weighed with our published formula.

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