Search  for anything...

18kW Tankless Water Heater Electric 240V WINTEMP, On Demand Instant Hot Water Heater, Up to 4.3 GPM, with LED Temperature Display, Whole House Hot Water Supply, WiFi Control, ETL Certified

  • Based on 106 reviews
Condition: New
Checking for the best price...
$279.99 Why this price?
Save $40.00 was $319.99

Buy Now, Pay Later


As low as $46.67 / mo
  • – 6-month term
  • – No impact on credit to apply
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Apple Pay, and PayTomorrow. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

FREE 30-day refund/replacement

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.


Availability: Only 10 left in stock, order soon!
Fulfilled by Amazon

Arrives Friday, Jun 5
Order within 4 hours and 55 minutes
Available payment plans shown during checkout

Protection Plan Protect Your Purchase
Checking for protection plans...

Model: WT-WN18K


Features

  • Important Note: Ensure this tankless water heater meets your installation requirements, 150 Amp Household Service Recommended. The WN18 model is rated at 18KW (240V) with a maximum amperage of 75A. It requires 2 x 40 Amp DP breakers and 2 x 8/2 AWG wiring with ground. The unit dimensions are 11.1 (W) x 19.1 (H) x 4 (D), the water connection is 3/4" NPT
  • Stable Water Temperature: Automatically adjusts energy consumption based on incoming water temperature and flow rate to ensure maximum efficiency, continuous stable temperature, and optimal power usage. Its maximum hot water output is 4.3 gallons per minute. It is perfect for residential shower use, eliminating the need to wait for preheating. Theres no longer any concern about running out of hot water in the tank, and you wont experience temperature fluctuations during your shower
  • Energy Saving: The self-regulating technology automatically adjusts power based on real-time water flow and temperature settings. When the water flow decreases, the system reduces power to save energy; when not in use, it consumes no electricity, achieving up to 99% energy savings. Compared to traditional tank water heaters, it is more energy-efficient and suitable for 2-3 points of use in the home
  • Space Saving: The WN18 features a wall-mounted compact design, occupying 90% less space compared to traditional tank water heaters. It is suitable for tight areas and can be easily installed anywhere. It provides an endless supply of hot water in a short time without the need to wait for preheating. Equipped with remote WiFi control, you can adjust the temperature without being near the water heater
  • Safe Usage: Safety is always WINTEMPs top priority. The product features multiple safety protections, including leakage protection, overheat protection, and dry-fire protection, and is ETL certified to fully ensure your safety, allowing you to enjoy hot water anytime, anywhere with peace of mind. We also provide a 2-year return and exchange warranty along with long-term professional technical support to give you worry-free use

Brand: WINTEMP


Power Source: ac


Product Dimensions: 11.1"W x 19.1"H


Special Feature: LED Display, Overheat Protection


Color: Gray


Power Source: ac


Special Features: LED Display, Overheat Protection


Wattage: 18000 watts


Voltage: 240 Volts


Flow Rate: 4.3 Gallons Per Minute


Maximum Temperature: 140 Degrees Fahrenheit


Heat Output: 18 Kilowatts


Efficiency: High Efficiency


Maximum Pressure: 130 Pound per Square Inch


Mount Type: Wall


Is Electric: Yes


Smart Home Compatibility: Smart Home Compatible


Color: Gray


Style Name: 18kW


Item Dimensions W x H: 11.1"W x 19.1"H


Item Weight: 12 Pounds


Item Depth: 4


Brand Name: WINTEMP


Model Number: WT-WN18K


Manufacturer: WINTEMP


Manufacturer Warranty Description: 2 Year


Manufacturer Part Number: WN18


Included Components: Water Heater


Unit Count: 211.68 Ounce


Material Type: Acrylonitrile Butadiene Styrene


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Friday, Jun 5

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews


  • Perfect fit for me, do your own research
Model: WT-WN18K
So ive had the product for a few weeks now and feel safe on writing a review. The day I ordered this was the day my tank water heater failed and started to flood my back room. Not wanting to deal with that problem ever again, I decided to take a chance on the product. Install was super easy...mostly but at no fault to the product on its own. It requires 2 lengs of 8-2wire. Which roughly ran me at 50 feet loose from home depot about $160. It also need two 40-amp double pole breakers which were $40 each. New pex and fittings to re-route the water lines because I had to wasnt the worst. Overall I think my entire install done by myself and a buddy was, with the product itself $600 with the bulk being split between the unit and the breakers. Now onto install. It has a sheet of paper you screw into at the marked holes. No guessing just simple and straightforward. Pull the paper off after, and hang on it. I was suffering with a shoulder injury from work and could lift this thing one handed, it weighs less than 20lbs. Hardest part was rewiring which doesn't fall under the products fault, just have never done it before. Speaking of wiring, you'll need a small screwdriver to attach the wires inside. I had it installed and running in less than 12 hours from start to finish. Simple, easy to do install and has been working BETTER than the old hot water heater. Before I could get meh warm water out maybe just over lukewarm, now its actually hot and, for the most part, stays hot. There are minor fluctuations with temp but really not bad at all. Now pay attention!!! I live in an old trailer with a house built around it from the 60's because whats code back then. I only have 2 sinks, kitchen and bathroom, a samsung front loading washing machine and a shower. Its perfect for my size and needs but may not be stronger for a larger home with more demand or further distance to run. Do your research. My wife and I are also gone about 90% of the day for work most days so it isnt generating hot water and using electric when we aren't home, so it was the right choice for us. Larger homes with kids and high demand may not benefit from this product type. ... show more
Reviewed in the United States on October 13, 2025 by Joshua Kolar

  • Water Heater
Model: WT-WN36K
This is a fantastic water heater. Easy to install, more compact in size and very efficient. It is one of the best units I have ever purchased.
Reviewed in the United States on February 28, 2026 by Luz Ramos

  • Good value, great customer support
Model: WT-WN27K
Installs easily, heats well and maintains a good temperature We had a small issue a couple months after our initial install due to my well going out This was nothing to do with the quality of the heater but dirt from the restart of the well clogged the flow of water coming in. Customer services was great. They responded quickly, diagnosed the problem and was able to explain how to remedy the problem so that we had hot water again in no time. We are very pleased with this product overall. It is a good product for the money with excellent customer support. ... show more
Reviewed in the United States on April 1, 2026 by Elizabeth Kumler

  • Not worth trying (under self review)
Update: 4-3-24 This company has reached out to me and we are currently going through a process of examining a similar unit in order to clear up any issues. I will report back on my findings after this is complete. ———————— I bought this unit to replace a unit we purchased in the past that ended up not working. Pro’s: -if you already have the smart home app that connects to this - connection is SUPER easy & the app is highly responsive when it works -it’s a good looking case on your wall -the over all heaviness to the unit is not too bad. Con’s: (they outweigh the pro’s) -the case feels like cheap plastic -the front cover attaches to the unit via snap in clips which are HARD to detach when you need to open the unit for installation. -the holes for the electrical lines are very “not firm” and there is no clamp included to keep those power wires in place. They basically just pass through an open air hole & connect via small flathead screws to the units receiving power ports. -both inlet & outlets are the usual 3/4” you see on most units, BUT they are pretty close together which makes planning your pvc connections below a bit challenging. I choose pvc unions so that the connections could be screwed on independently, but i still have to space them 1 below the other(see photo) -the entire unit is expected to be mounted with picture style hanging holes in the rear case. It’s the kind where you measure the distance between holes screw in your screws & hope everything lines up when you go to hang it. There are better ways to design your mounting options & this company did not choose them. -hot water but only IF the flow rate isn’t too strong. If too much water passes through the unit too fast, this unit doesn’t even try to keep up. It just shuts off. -once you’ve got the flow rate dailed in, then it randomly stops producing that hot water again. -the app will literally show you in real time what the unit it doing. So i can load the app, stand at my kitchen sink, turn the hot water on & watch as it super heats the water. I’ll begin washing dishes & all of the sudden - the unit stops heating, goes into standby mode & gives up. So I’ll continue washing dishes in cold water & all of the sudden, the hot water will begin again. It’s really confusing. -no visible customer service. I went through Amazon support because that’s where i purchased it. Not once in the chat did the representative say they would contact the seller. All they said was i could get a refund & send the unit back so that’s what i am doing. Notes: my whole system is pex 1/2 with the exception of the 3/4” supply & return of the water heater. I ran 3 1/2” lines of hot water. 1 to my bathroom sink, 1 to my tub, 1 to my kitchen sink. After learning this unit doesn’t perform with the correct installation, I bought a replacement & it’s already installed & working. Now i will return this unit & move forward. ... show more
Reviewed in the United States on January 6, 2024 by Justin

  • Great product for a great price
Model: WT-WN18K
A user-friendly product with excellent quality, suitable for everyone to use together, and the delivery speed is very fast
Reviewed in the United States on April 13, 2026 by James T. Gomoka

  • WINTEMP 27kW 240V, Whole House Hot Water Supply. Heats water and it does it well.
Model: WT-WN27K
I like the weight and ease of installation physically. I do not like the close proximity of the inlet and outlet connections as I did install a common maintenance disconnect system for descaling the heaters. Because of their closeness I had to use additional fittings to move the outlet to the left by some 3 to 4 inches. This increased cost of installation and numerous leaks dealing with TEFLON Tape and NPT Connections. This was made more difficult due to coefficient of expansion of BRASS Fittings and output Temperature. DO NOT SELECT WITHOUT 200 AMP 240 VOLT Single Phase Service. ... show more
Reviewed in the United States on November 21, 2025 by M. Thomas Schafer

  • Great customer service!!!
Model: WT-WN27K
I purchased this unit for a 3 bath home and it worked wonderfully! After about 4 months there was a slight issue with the water heater and I contacted Wintemp. They went over and beyond to assist me and the unit is up and running again! This is the best customer service that I have ever experienced!
Reviewed in the United States on March 9, 2026 by L.Spivey

Can't find a product?

Find it on Amazon first, then paste the link below.
Checking for best price...