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APUS 27 kW Electric, 240V

Product images: Amazon listings

APUS 27 kW Electric, 240V Review

7.4Good · out of 10#5 of 5 in our Whole-House Electric Tankless Heaters ranking

Written from the listing and 120 buyer reviews, not from our own use · How we rate

If you're after up to 6.5 GPM, the APUS 27 kW Electric (240V) delivers, with 27 kW of heating power and self-modulating power on top. One of our top 5 whole-house electric tankless water heaters, it is made for a whole house on electric in a warm or mild climate.

See current price ↗Prices change often: the listing shows today's.
Check the price on Amazon ↗ APUS 27 kW Electric, 240V (opens in a new tab)Affiliate link · price and stock on Amazon
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Specifications
BrandAPUS
CategoryElectric tankless water heaters
FuelElectric
Stated maximum flow6.5 GPM
Stated heating power27 kW
Stated voltage240 V
Temperature range86 to 140 °F
Breakers named in the listing3 × 40 A double-pole
Wire gauge8 AWG
Buyer reviews120 · 4.1/5
ASINB0FL73GY1F

Full listing title: APUS 27kW Electric Tankless Water Heater, 240V, Up to 6.5 GPM, 3s Instant

Listing evidence
Fuel27kW Full listing title
Stated maximum flow6.5 GPM Full listing title
Stated heating power27kW Full listing title
Stated voltage240V Full listing title
Updated October 2026
Exact listing, ASIN B0FL73GY1F
Rating from a published formula

Compared with its closest rivals

The two picks next to it in our whole-house electric tankless water heaters ranking, with their rating and a dated price.

Compare side by side ↗

WINTEMP WM-36kW Plus Electric, 240V

WINTEMP WM-36kW Plus Electric, 240V

7.6Very good · out of 10$699.98 Price on Sep 30, 2026 · may have changed
  • Stated: 8.7 GPM · 36 kW · 240 V
  • 60 buyer reviews
  • Electric tankless water heaters
See the review ↗
Stiebel Eltron Tempra 29 Plus

Stiebel Eltron Tempra 29 Plus

7.9Very good · out of 10$798.99 Price on Sep 30, 2026 · may have changed
  • Stated: 28.8 kW · 240 V
  • 451 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. Show that to your electrician first. Whether your panel has the room is the whole question, and the shower comes second.

Why it made our list

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
  • Star ratings come first for you: 4.1/5 is below the 4.3 average of this ranking
  • You simply want our top pick: that's the Rheem 18 kW Electric (240V) (9.3/10)

What APUS promises

The seller states, word for word, in the APUS 27 kW Electric (240V) listing:

  • Actual flow varies with inlet-water temperature, selected outlet temperature and household demand.
  • Adjust water temperature from 86°F–140°F in 1°F increments using the LED digital display.
  • Standard 3/4-inch NPT water connections support straightforward plumbing integration for permanent residential installations.
  • Fault information can be displayed when abnormal conditions are detected.

Their words and their figures, not our measurements. How steady your shower stays when someone opens the kitchen tap, and what's left of that flow in January, no listing can tell you.

APUS 27 kW Electric, 240V, view 3

Power, wiring and what's in the box

What the APUS 27 kW Electric (240V) listing names:

  • 27 kW
  • 240 V
  • 3 × 40 A double-pole breakers
  • 8 AWG wire
  • Up to 6.5 GPM
  • Self-modulating
  • 86 to 140 °F setpoint
  • Digital display

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

APUS 27 kW Electric, 240V, view 4

Price and availability

See current price ↗

We have no recent price on file for this listing, so we don't print an old one.

Budget for the electrician as well: 3 × 40 A double-pole breakers, thick wire from the panel and, if the panel is full, an upgrade.

The button opens the exact listing (ASIN B0FL73GY1F), where today's price, stock and seller apply.

APUS 27 kW 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

The APUS 27 kW Electric (240V) earns its place with up to 6.5 GPM and 27 kW of heating power. 120 buyers have had their say, which is plenty to go on. Where it falls short: their 4.1/5 average sits under the 4.3 of this ranking. We'd pick it if you run one shower and the kitchen tap at once, rarely more; otherwise, put it next to the WINTEMP WM-36kW Plus Electric (240V) first.

Check the price on Amazon ↗ APUS 27 kW Electric, 240V (opens in a new tab)Affiliate link · price and stock on AmazonSee the whole-house electric tankless water heaters ranking →

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 between 86 and 140 °F.

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 4.1/5, a decent record, slightly below this ranking's 4.3 average. 120 reviews is a fair sample, enough for the average to mean something.

The numbers
Buyer rating
4.1/5
Reviews
120
This ranking's average
4.3/5

The one thing we'd check first

Before the APUS 27 kW Electric (240V) ships, 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 APUS 27 kW Electric (240V) stacks up against the closest alternative in our ranking, the WINTEMP WM-36kW Plus Electric (240V).

CriterionAPUS 27 kW Electric, 240VWINTEMP WM-36kW Plus Electric, 240V
Our rating7.4/107.6/10
Heating power27 kW36 kW
Max flow6.5 GPM8.7 GPM
WarrantyNot stated2 years
Buyer reviews120 · 4.1/560 · 4.3/5

Pick the WINTEMP WM-36kW Plus Electric (240V) if you want our higher-rated option (7.6/10), with more power (36 kW) and more stated flow (8.7 GPM).

Compare side by side ↗See the WINTEMP WM-36kW Plus Electric, 240V review →
The score in detail

How we rated it

Our score: 7.4/10

Buyer rating (45%)

36.9 / 45

4.1/5 average

Review volume (35%)

19.7 / 35

120 buyer reviews

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 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 APUS 27 kW Electric (240V) any good?

We rate it 7.4/10 (good), #5 of 5 in our whole-house electric tankless water heater ranking. It is based on 120 buyer reviews averaging 4.1/5 and the specifications stated in the listing.

How much hot water can the APUS 27 kW 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 APUS 27 kW 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.

What do you get with the APUS 27 kW Electric (240V)?

Its listing states up to 6.5 GPM, 27 kW of heating power and self-modulating power. 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 APUS 27 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, 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 APUS 27 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 APUS 27 kW Electric (240V) yourselves?

No, we haven't used it ourselves. Everything on this page comes from its listing and 120 buyer reviews, read line by line and weighed with our published formula.

Keep comparing

If the APUS 27 kW Electric, 240V hasn't sold you yet, see where it ranks or browse all electric tankless water heaters.

Where it ranks

Best Whole-House Electric Tankless Water Heaters in 2026 →
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