Product images: Amazon listings

WINTEMP WN-18kW Electric, 240V Review

Name: WINTEMP WN-18kW Electric, 240V
Brand: WINTEMP
SKU: B0DLKQY4B3

7.2Good · out of 10Not in our top-5 rankings

Written from the listing and 203 buyer reviews, not from our own use · How we rate

The WINTEMP WN-18kW Electric (240V) packs 18 kW at 240 V, an element that only draws what it needs and Wi-Fi control from your phone into one electric tankless heater. It suits a southern house with warm tap water and no gas line, and its sibling listing, the WINTEMP WN-36kW Electric (240V), holds #2 in our whole-house electric tankless water heater ranking.

Variants of this model

These 203 buyer reviews (4.4/5) are shared by the WN-36kW Electric, 240V and WN-18kW Electric, 240V listings, so they speak for the family more than for one size.

WINTEMP WN-36kW Electric, 240V · WN-36kW · 8.1/10

Price$279.98Price 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	WINTEMP
Category	Electric tankless water heaters
Fuel	Electric
Stated heating power	18 kW
Stated voltage	240 V
Breakers named in the listing	2 × 40 A double-pole
Total current	150 A
Wire gauge	2 AWG
Wi-Fi	Built in, per the listing
Stated warranty	2 years
Buyer reviews	203 · 4.4/5, shared by the WINTEMP listing family (2 variants)
ASIN	B0DLKQY4B3

Full listing title: WINTEMP 18kW Electric Tankless Water Heater 240V ETL Certified WiFi

Listing evidence

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

Updated October 2026

Exact listing, ASIN B0DLKQY4B3

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 ↗

WINTEMP WN-18kW Electric, 240V

7.2Good · out of 10$279.98 Price on Sep 30, 2026 · may have changed

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

This product ↑

Stiebel Eltron Tempra 20 Trend

7.0Good · out of 10$544.43 Price on Sep 30, 2026 · may have changed

Stated: 19.2 kW · 240 V
103 buyer reviews
Electric tankless water heaters

See the review ↗

EcoSmart ECOS 18, 18 kW 240V

7.5Very good · out of 10See current price ↗

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

See the review ↗

18 kW at 240 V

The heating power the listing states. At 240 V it draws about 75 A, and the listing asks for 2 × 40 A double-pole breakers on 2 AWG wire. That's the line to show your electrician before anything else: the panel decides whether this fits, not the shower.

What it has going for it

What changes in the morning shower rush

Self-modulating. It draws only the power the flow and the setpoint need, instead of slamming every element on. Steadier temperature, and no wasted amps on a summer afternoon.

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.

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 want the shower temperature to stay put
You like to see what your appliances are doing

Skip it if…

Your panel is already close to full: 18 kW is about 75 A at 240 V
Your tap water comes in icy in January: 18 kW gives about 1.9 GPM at a 63 °F rise

What WINTEMP promises

The seller states, word for word, in the WINTEMP WN-18kW Electric (240V) listing:

The WN18 model is rated at 18KW (240V) with a maximum amperage of 75A.
Its maximum hot water output is 4.3 gallons per minute.
Self-modulating technology automatically adjusts power consumption based on real-time water flow and the set temperature.

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.

Power, wiring and what's in the box

What the WINTEMP WN-18kW Electric (240V) listing names:

18 kW
240 V
150 A total draw
2 × 40 A double-pole breakers
2 AWG wire
Self-modulating
Wi-Fi app control
CSA, ETL or UL mark named

Warranty & support: 2-year warranty, as stated in the listing · CSA, ETL or UL certification named in the listing.

That is the maker's promise, not ours. Keep the invoice, register the WINTEMP WN-18kW Electric (240V) if the maker asks, and read the install conditions: many tankless warranties need a licensed install and regular flushing.

For the WINTEMP WN-18kW Electric (240V), the installation manual settles the breakers and the wire.

Price and cost per kW

$279.98 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 $15.55 (price ÷ stated kW, our arithmetic). That puts it in the cheaper third of the 27 whole-house electric tankless heaters we have a price and a stated power for.

The online price is the heater alone. 2 × 40 A double-pole breakers, heavy-gauge wire and the electrician's visit are extra, and an older panel may need an upgrade first.

The button opens the exact listing (ASIN B0DLKQY4B3), where today's price, stock and seller apply. Sizes and variants of the same family often sit at different prices.

A better fit for your house and panel?

Colder tap water where you live? The Stiebel Eltron Tempra 29 Plus (7.9/10) is rated 28.8 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.

Our take

The verdict

What we'd buy the WINTEMP WN-18kW Electric (240V) for is 18 kW at 240 V, with an element that only draws what it needs as a bonus. 203 buyers give it 4.4/5, which is a solid sign. The one thing that bugs us: no word on the flow. Before you decide, put it next to the CAMPLUX 27 kW Electric (240V).

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

Living with it

Install day

2 new 40 A breakers, 2 AWG wire, 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, and the power steps up and down with the flow (self-modulating, per the listing). 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 4.4/5, a strong record, above our ranked picks' 4.3 average. 203 reviews is a fair sample, enough for the average to mean something. The same reviews appear on both variants of the WINTEMP family, so they describe the family rather than this exact variant.

The numbers

Buyer rating: 4.4/5
Reviews: 203
Ranked picks' average: 4.3/5

The one thing we'd check first

Before you order the WINTEMP WN-18kW Electric (240V), check your panel: it asks for 2 × 40 A double-pole breakers and 2 AWG wire, 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 WINTEMP WN-18kW Electric (240V) stacks up against the closest alternative, the CAMPLUX 27 kW Electric (240V).

Criterion	WINTEMP WN-18kW Electric, 240V	CAMPLUX 27 kW Electric, 240V
Our rating	7.2/10	7.2/10
Heating power	18 kW	27 kW
Breakers	2 × 40 A	Not stated
Warranty	2 years	Not stated
Buyer reviews	203 · 4.4/5	141 · 4.3/5

Both score 7.2/10. The CAMPLUX 27 kW Electric (240V) adds more power (27 kW), while the WINTEMP WN-18kW Electric (240V) brings a longer stated warranty (2 years).

Compare side by side ↗See the CAMPLUX 27 kW Electric, 240V review →

The score in detail

How we rated it

Our score: 7.2/10

Buyer rating (45%)

39.6 / 45

4.4/5 average

Review volume (35%)

21.9 / 35

203 buyer reviews, shared by 2 variants

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 of the review pool shown on both variants of the WINTEMP listing family, 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 WINTEMP WN-18kW Electric (240V) any good?

We rate it 7.2/10 (good). It is based on 203 buyer reviews averaging 4.4/5, shared by the WINTEMP listing family (2 variants) and the specifications stated in the listing.

How much hot water can the WINTEMP WN-18kW 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 WINTEMP WN-18kW 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.

Are the reviews specific to the WINTEMP WN-18kW Electric (240V)?

No. The same review pool appears on every variant of the WINTEMP listing family: 203 reviews averaging 4.4/5 on the WINTEMP WN-36kW Electric, 240V and WINTEMP WN-18kW Electric, 240V. The count therefore describes the family, not this exact variant, and in our rankings the family takes a single slot.

What do you get with the WINTEMP WN-18kW Electric (240V)?

Its listing states 18 kW of heating power, self-modulating 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 WINTEMP WN-18kW 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 WINTEMP WN-18kW 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 WINTEMP WN-18kW Electric (240V) yourselves?

No, we haven't used it ourselves. Everything on this page comes from its listing and 203 buyer reviews, read line by line and weighed with our published formula.

Electric tankless water heaters ↗All WINTEMP products Comparison tool All product reviews