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MRNIU 36 kW Electric, 240V Review

Name: MRNIU 36 kW Electric, 240V
Brand: MRNIU
SKU: B0F9DDXLB5

5.9Fair · out of 10Rated from the listing's specs, no buyer reviews yet

Written from the listing and 5 buyer reviews, not from our own use · How we rate

The MRNIU 36 kW Electric (240V) keeps it simple: an electric tankless heater with 36 kW at 240 V. It suits a whole house on electric in a warm or mild climate, at 5.9/10 on our rating.

Price$324.90Price 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	MRNIU
Category	Electric tankless water heaters
Fuel	Electric
Stated heating power	36 kW
Stated voltage	240 V
Buyer reviews	5 · 4.4/5
ASIN	B0F9DDXLB5

Full listing title: 36kW 240 Volts On Demand Instant Endless Water Heater Tankless Water Heater Electric with LED Temperature Display for Residential Whole House Shower, Space Saving, IPX4

Listing evidence

Fuel	36kW Full listing title
Stated heating power	36kW Full listing title
Stated voltage	240 Volts Full listing title

Updated October 2026

Exact listing, ASIN B0F9DDXLB5

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 ↗

MRNIU 36 kW Electric, 240V

5.9Fair · out of 10$324.90 Price on Sep 30, 2026 · may have changed

Stated: 36 kW · 240 V
5 buyer reviews
Electric tankless water heaters

This product ↑

Rheem RETEX-36 Performance, 36 kW

5.9Fair · out of 10$752.99 Price on Sep 30, 2026 · may have changed

Stated: 6 GPM · 36 kW
Electric tankless water heaters

See the review ↗

ThermoMate 27 kW Electric

6.2Fair · out of 10$446.49 Price on Sep 30, 2026 · may have changed

Stated: 6.6 GPM · 27 kW · 240 V
36 buyer reviews
Electric tankless water heaters

See the review ↗

36 kW at 240 V

The heating power the listing states. At 240 V it draws about 150 A. Before you think about showers, your electrician has to say yes to that number at the panel in the garage.

Warm tap water or a cold January?

Warm tap water: where it comes in around 62 °F (much of the South), 36 kW gives about 5.7 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 3.9 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…

Your house has no gas and a 200 A panel with room to spare

Skip it if…

You want self-modulating power: the listing doesn't say it modulates
Your panel is 100 A or already busy: 36 kW at 240 V is about 150 A on its own
You want a long review record: only 5 buyer reviews so far

Power, wiring and what's in the box

What the MRNIU 36 kW Electric (240V) listing names:

36 kW
240 V

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

Price and cost per kW

$324.90 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 $9.02 (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. New 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 B0F9DDXLB5), where today's price, stock and seller apply.

A better fit for your house and panel?

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.

Want it to draw only what it needs? The WINTEMP WN-36kW Electric, 240V (8.1/10) is self-modulating, per its listing.

Our take

The verdict

The MRNIU 36 kW Electric (240V) is about 36 kW at 240 V, and it doesn't pretend to be more. Only 5 buyers have rated it so far (4.4/5), so treat the score as an early read. The catch with this MRNIU electric tankless heater: no stated self-modulation, while most picks here have it. We'd pick it if your house has no gas and a 200 A panel with room to spare; otherwise, put it next to the ThermoMate 27 kW Electric 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, 36 kW gives about 3.9 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. Only 5 reviews so far, and our formula damps averages built on fewer than 50.

The numbers

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

The one thing we'd check first

Before the MRNIU 36 kW Electric (240V) goes in your cart, check your panel: 36 kW at 240 V is roughly 150 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, 36 kW gives about 3.9 GPM with 42 °F winter water and 5.7 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 MRNIU 36 kW Electric (240V) stacks up against the closest alternative, the ThermoMate 27 kW Electric.

Criterion	MRNIU 36 kW Electric, 240V	ThermoMate 27 kW Electric
Our rating	5.9/10	6.2/10
Heating power	36 kW	27 kW
Max flow	Not stated	6.6 GPM
Breakers	Not stated	150 A total
Self-modulating	Not stated	Stated
Buyer reviews	5 · 4.4/5	36 · 4.7/5

Pick the ThermoMate 27 kW Electric if you want our higher-rated option (6.2/10), with more stated flow (6.6 GPM) and self-modulating power; stay with the MRNIU 36 kW Electric (240V) for more power (36 kW).

Compare side by side ↗See the ThermoMate 27 kW Electric review →

The score in detail

How we rated it

Spec-based rating on a 4.5–8.5 scale: 4.5 + average of the 4 criteria × 0.4. Capped at 8.5 because no customer evidence is included.

Key specifications

4 / 10

Build, warranty & certifications

3 / 10

Listing documentation

3 / 10

Fit & compatibility

4 / 10

This product has no captured buyer-review record yet, so its rating comes from the documented listing alone: four criteria scored out of 10 (key specifications; build, warranty and certifications; listing documentation; fit and compatibility), placed on a 4.5–8.5 scale. Read the full methodology.

Read the methodology →

Frequently asked questions

Is the MRNIU 36 kW Electric (240V) any good?

We rate it 5.9/10 (fair). The rating comes from its documented listing alone, as no customer-review record is captured yet.

How much hot water can the MRNIU 36 kW Electric, 240V deliver?

The listing states a heating power of 36 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 MRNIU 36 kW Electric, 240V need?

The listing states 240 V and 36 kW. At 240 V, that is roughly 150 A. A licensed electrician checks the panel, the breakers and the wiring before it goes on the wall.

What do you get with the MRNIU 36 kW Electric (240V)?

Its listing states 36 kW of heating 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 MRNIU 36 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, 36 kW gives about 3.9 GPM with 42 °F winter water and 5.7 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 MRNIU 36 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 MRNIU 36 kW Electric (240V) yourselves?

No, we haven't used it ourselves. Everything on this page comes from its listing and 5 buyer reviews, read line by line and weighed with our published formula.

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