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WINTEMP WM-27kW Plus Electric, 240V Review

Name: WINTEMP WM-27kW Plus Electric, 240V
Brand: WINTEMP
SKU: B0GBVTHYJB

7.3Good · out of 10Not in our top-5 rankings

Written from the listing and 60 buyer reviews, not from our own use · How we rate

The WINTEMP WM-27kW Plus Electric (240V) ticks most of the boxes we care about: a 6.5 GPM maximum flow, 27 kW at 240 V and an element that only draws what it needs. It suits a home without gas and with a big panel, and its sibling listing, the WINTEMP WM-36kW Plus Electric (240V), holds #4 in our whole-house electric tankless water heater ranking.

Variants of this model

These 60 buyer reviews (4.3/5) are shared by the WM-36kW Plus Electric, 240V and WM-27kW Plus Electric, 240V listings, so they speak for the family more than for one size.

WINTEMP WM-36kW Plus Electric, 240V · WM-36kW Plus · 7.6/10

Price$439.98Price 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 maximum flow	6.5 GPM
Stated heating power	27 kW
Stated voltage	240 V
Breakers named in the listing	3 × 40 A double-pole
Total current	200 A
Wire gauge	8 AWG
Wi-Fi	Built in, per the listing
Stated warranty	2 years
Buyer reviews	60 · 4.3/5, shared by the WINTEMP listing family (2 variants)
ASIN	B0GBVTHYJB

Full listing title: Wintemp 27kW Tankless Water Heater Electric 240V WiFi, ETL Certified

Listing evidence

Fuel	27kW Full listing title
Stated maximum flow	up to 6.5 GPM Listing text
Stated heating power	27kW Full listing title
Stated voltage	240V Full listing title

Updated October 2026

Exact listing, ASIN B0GBVTHYJB

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 WM-27kW Plus Electric, 240V

7.3Good · out of 10$439.98 Price on Sep 30, 2026 · may have changed

Stated: 6.5 GPM · 27 kW · 240 V
60 buyer reviews
Electric tankless water heaters

This product ↑

CAMPLUX 27 kW Electric, 240V

7.2Good · out of 10$302.62 Price on Sep 30, 2026 · may have changed

Stated: 27 kW · 240 V
141 buyer reviews
Electric tankless water heaters

See the review ↗

Stiebel Eltron Tempra 24 Trend

7.2Good · out of 10$514.23 Price on Sep 30, 2026 · may have changed

Stated: 24 kW · 240 V
93 buyer reviews
Electric tankless water heaters

See the review ↗

27 kW at 240 V

The heating power the listing states. At 240 V it draws about 113 A, and the listing asks for 3 × 40 A double-pole breakers on 8 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

6.5 GPM max. That is the headline figure, usually at a modest temperature rise. Our calculator counts a shower at 2 GPM, so think two showers and a kitchen tap on paper, less when the water comes in cold.

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.

Warm tap water or a cold January?

Warm tap water: where it comes in around 62 °F (much of the South), 27 kW gives about 4.3 GPM of 105 °F water on our calculator's maths. That's two 2 GPM showers at once.

A cold January: where it comes in at 42 °F, it's about 2.9 GPM, one 2 GPM shower at a time. 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 run one shower and the kitchen tap at once, rarely more
Your house has no gas and a 200 A panel with room to spare
You want the shower temperature to stay put

Skip it if…

Your panel is 100 A or already busy: 27 kW at 240 V is about 113 A on its own

What WINTEMP promises

The seller states, word for word, in the WINTEMP WM-27kW Plus Electric (240V) listing:

The WM27V model is rated at 27kW (240V) with a maximum current of 113A.
Advanced flow control technology automatically maintains water temperature.
When the flow decreases, it reduces energy use—and when no hot water is needed, it goes into true zero-energy standby.
The WM27V features a compact wall-mounted design, measuring 15.9" (H) × 13" (W) × 4.2" (D).
Temperature can be set between 86°F and 140°F.

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.

WINTEMP WM-27kW Plus Electric, 240V, view 3

Power, wiring and what's in the box

What the WINTEMP WM-27kW Plus Electric (240V) listing names:

27 kW
240 V
200 A total draw
3 × 40 A double-pole breakers
8 AWG wire
Up to 6.5 GPM
Self-modulating
Digital display
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 WM-27kW Plus Electric (240V) if the maker asks, and read the install conditions: many tankless warranties need a licensed install and regular flushing.

Breakers and wire gauge are in the installation manual, and it overrides anything above; your electrician reads it first.

WINTEMP WM-27kW Plus Electric, 240V, view 4

Price and cost per kW

$439.98 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 $16.30 (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 electrician comes on top: 3 × 40 A double-pole breakers, heavy wire and, in some houses, a panel upgrade.

The button opens the exact listing (ASIN B0GBVTHYJB), where today's price, stock and seller apply. Sizes and variants of the same family often sit at different prices.

WINTEMP WM-27kW Plus Electric, 240V, view 5

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.

Panel short on spare amps? The Rheem 18 kW Electric, 240V (9.3/10) is rated 18 kW, about 75 A at 240 V.

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

Our favourite thing about the WINTEMP WM-27kW Plus Electric (240V) is a 6.5 GPM maximum flow, closely followed by 27 kW at 240 V. Only 60 buyers have rated it so far (4.3/5), so treat the score as an early read. Honestly, the catch: the heater is the cheap part next to the panel work an electrician may need. We'd pick it if you run one shower and the kitchen tap at once, rarely more; otherwise, put it next to the APUS 27 kW Electric (240V) first.

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

Living with it

Install day

3 new 40 A breakers, 8 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, 27 kW gives about 2.9 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 4.3/5, a solid record, right on our ranked picks' 4.3 average. 60 reviews is still a modest pile, so a handful of new ones can move it. 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: 4.3/5
Reviews: 60
Ranked picks' average: 4.3/5

The one thing we'd check first

Before the WINTEMP WM-27kW Plus Electric (240V) goes in your cart, check your panel: it asks for 3 × 40 A double-pole breakers and 8 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, 27 kW gives about 2.9 GPM with 42 °F winter water and 4.3 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 WM-27kW Plus Electric (240V) stacks up against the closest alternative, the APUS 27 kW Electric (240V).

Criterion	WINTEMP WM-27kW Plus Electric, 240V	APUS 27 kW Electric, 240V
Our rating	7.3/10	7.4/10
Heating power	27 kW	27 kW
Max flow	6.5 GPM	6.5 GPM
Warranty	2 years	Not stated
Buyer reviews	60 · 4.3/5	120 · 4.1/5

Pick the APUS 27 kW Electric (240V) if you want our higher-rated option (7.4/10); stay with the WINTEMP WM-27kW Plus Electric (240V) for a longer stated warranty (2 years) and a higher buyer rating (4.3/5).

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

The score in detail

How we rated it

Our score: 7.3/10

Buyer rating (45%)

38.7 / 45

4.3/5 average

Review volume (35%)

16.9 / 35

60 buyer reviews, shared by 2 variants

Documented specifications (20%)

17.2 / 20

86/100 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 WM-27kW Plus Electric (240V) any good?

We rate it 7.3/10 (good). It is based on 60 buyer reviews averaging 4.3/5, shared by the WINTEMP listing family (2 variants) and the specifications stated in the listing.

How much hot water can the WINTEMP WM-27kW Plus Electric, 240V deliver?

The listing states a maximum flow of 6.5 GPM and a heating power of 27 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 WM-27kW Plus Electric, 240V need?

The listing states 240 V and 27 kW. At 240 V, that is roughly 113 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 WM-27kW Plus Electric (240V)?

No. The same review pool appears on every variant of the WINTEMP listing family: 60 reviews averaging 4.3/5 on the WINTEMP WM-36kW Plus Electric, 240V and WINTEMP WM-27kW Plus 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 WM-27kW Plus Electric (240V)?

Its listing states up to 6.5 GPM, 27 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 WM-27kW Plus 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, 27 kW gives about 2.9 GPM with 42 °F winter water and 4.3 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 WM-27kW Plus 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 WM-27kW Plus Electric (240V) yourselves?

No, we haven't used it ourselves. Everything on this page comes from its listing and 60 buyer reviews, read line by line and weighed with our published formula.

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