Tankless Water Heater Electric 18kW 208~240 Volt, ThermoMate On Demand Instant Endless Hot Water Heater, Self Modulating Saving Energy for Residential Whole House Shower, 76A GRAY
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This item is eligible for return within 30 days of receipt
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Availability:
In Stock.
Arrives
Thursday, Sep 25
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Style: 18kW
Features
- [Instant Unlimited Hot Water] - On demand tankless electric water heater, providing hot water in 3 seconds when you need it and as long as you need, eliminating wait time, never run out of hot water again and No More cold shower. Requires 80Amp breaker (2 Sets of Double-pole 40AMP Breakers)
- [Save Money and Space] - Self-modulating technology regulating the amount of energy required to heat water only when you need it with 99.8% efficient, saving up to 60% on water heating cost comparing to traditional tank water heater. Wall mounted compact size with no water tank, convenient for any spaces, saving floor space and fitting into tight spaces.
- [Easy Installation & Safety Protection] - ETL certified with overheating protection, auto stop heating when detecting no water, quality workmanship for leakage protection
- NOTE - Make sure this water heater is the correct size for your hot water need: 18kW 208 ~ 240V (adjustable) draw max 76amp; Required breaker 2 x Double-POLE 40AMP; Wire gauge 2 x 8AWG; Unit size 17.12" x 13.12" x 3.12"; Water connection 3/4" NPT.
Brand: thermomate
Product Dimensions: 13.12"W x 17.12"H
Special Feature: Instant hot water, Leaking free and maintenance free heating element
Color: Gray
Wattage: 18000 watts
Brand: thermomate
Product Dimensions: 13.12"W x 17.12"H
Special Feature: Instant hot water, Leaking free and maintenance free heating element
Color: Gray
Wattage: 18000 watts
Voltage: 240 Volts (AC)
Maximum Temperature: 1.4E+2 Degrees Fahrenheit
Heat Output: 18 Kilowatts
Efficiency: 99.8%
Maximum Pressure: 150 Pound per Square Inch
Mounting Type: Wall
Is Electric: Yes
Manufacturer: thermomate
UPC: 750139327591
Manufacture Year: 2024
Part Number: ET180
Item Weight: 21.5 pounds
Item model number: ET180
Is Discontinued By Manufacturer: No
Size: 240V/18kW
Finish: Galvanization
Amperage Capacity: 76 Amps
Maximum Power: 18000 Watts
Installation Method: Wall-Mounted
Item Package Quantity: 1
Temperature Range: 80-140 Degrees Fahrenheit
Certification: ETL
Special Features: Instant hot water, Leaking free and maintenance free heating element
Usage: Inside; Professional
Included Components: Mount Kit
Batteries Included?: No
Batteries Required?: No
Date First Available: November 3, 2020
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Thursday, Sep 25
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.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Style: 18kW
***UPDATE*** Month 1 after installing the unit, my electric bill went from $350 the prior month down to $230 the following month. So this has had clear and immediate cost savings for my electrical usage. Very happy with the results! ---------------------- I wanted to replace my traditional tank water heater with an electric tankless, so I did hours of research and comparing models and options. Finally settled on this unit in the 18KW size to fit my needs. I wanted to the next higher up but my electrical panel and home service capacity made that a risk choice. However, I'm delighted at how well the 18kw model works for my whole home use-case. Thankfully due to having an EV, I already had a conveniently located sub-panel installed. All I had to do was upgrade the capacity on that sub-panel, which was as simple as buying a larger breaker and making sure the existing wiring was up to the task. Ended up taking out the old 30amp breaker the tank water heater used out of the main panel, installing a 40-amp dual pole breaker there in its place, then upgraded my sub-panel to 100amps, and finally installing the second 40-amp dual pole breaker in the sub-panel. Ran all the 8 AWG wire to the location where I wanted to mount the water heater and used an appropriate amount of conduit and secured to the wall, which for me thankfully was only about 6 feet of distance. If you have complex electrical situations happening, definitely call in a licensed electrician. At this point it was an easy install to mount the unit on the wall, secure the wiring which was intuitive, and wall labeled. I didn't find any of the wiring or instructions to be wrong or confusing so thats a plus. The moment of truth then arrived, powering on the unit and setting the desired water temperature. A few quick tests and bingo, hot water. Its not been 3 days since the install and multiple showers, laundry, running the dishwasher, etc. No issues whatsoever. In fact, this unit outperforms the tank water heater we had before. My family now reports that they have to set the faucet to a less hot position than they did previous during showers. The water flow is perfect even when both showers are running full blast. We get consistently hot water and don't have to adjust it multiple times during the course of the shower as we did with the old water heater. Overall, very happy with the performance of this unit! My application is a single story, 2 full bath home, so I wanted something that could handle two concurrent showers and the occasional hand washing or laundry running at the same time. And I'm thrilled to say that it works for me better than expected. I also love that its a newer design that separates the heating element from the water flow path, which means less maintenance and easier repairs if something goes wrong in the future. Time will tell in terms of durability, but I was impressed with the quality of the build, its well-made and appears to be a thoughtful and clean design. Other units I checked out before buying this one looked sloppy, not as well designed. I'm so glad I chose this model. Obviously do your research on your electrical capacity, sizing for your use-case, etc. All I can say is that it works for me in my whole house use-case in Central Florida. Northern cold climates may need a more powerful unit. For me, I've got no doubt this will be more efficient and save me money on my monthly electric bill compared to the old unit electrical consumption. To top it all off, I got this on Amazon Prime Day using a deal and the cost was unbeatable for what I got in this unit. Super happy, will update the review in the future should anything else happen to change my mind.
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Reviewed in the United States on October 17, 2023 by Joe
Style: 6kW
Lifesaver. Primary 50 gallon water heater developed pinhole leak. Replacement was two weeks away. After 3 days of 40 degree showers, made the move to a low-flow, tankless to at least warm up the water. This was the largest I could use on an existing 30amp circuit. Pleasantly surprised, and impressed that it was capable of providing enough hot water to comfortably (110* - 115*) take a hot show, just at a lower than normal flow (.75 gal/hr). This unit is sized for a sink. For over two weeks while the replacement was on order - this unit performed flawlessly and enabled dishwasher, clothes washer and most importantly hot showers to continue. The manual is sparse, but this is as simple as it gets - 1/2" inlet/outlet - on/off button and temp adjustment. Unit doesn't start to heat water until sufficient flow is seen (indicated on panel). After that hot water is instant and lasts until water draw stops. Panel will also indicate if you are pulling too much water for effective heating. Only thing I could possibly think of making this better would be to onshore the production to the same area in South Carolina where developed. If you are looking for a small instant water heater, can't ask for more from this unit.
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Reviewed in the United States on May 7, 2025 by Stephen Hurff
Style: 11kW
I’ve been using mine since 2023 and it has worked pretty well. It feeds a kitchen sink, bathroom sink and shower/tub with no problem. Gets really hot. I’m happy so far
Reviewed in the United States on August 1, 2025 by Rob L Hock
Style: 6kW
This replaced a Bosch Tankless unit that failed when the electricity shorted to the water and did significant damage to the connecting plumbing, so it was important to replace it with one that separates the water from the electricity. After month of use it is working to my satisfaction at my personal bathroom sink. It takes a little longer to reach the set temperature than the older Bosch unit did but I am satisfied with the unit. I like being able to manually control the temperature and have a display to see when it operates. it is small and was easy for me, at 82, to install and connect it up since I already had 220VAC wired from the failed Bosch unit. I gave this a 4 star rating because the manual and mounting bracket was not in the shipped box. Rather than return the unit and order another I contacted Thermomate Support and they sent me the manual and bracket; however, it took about a month to receive the missing items. This biggest problem for most people is having to get 220VAC to the unit of which was not a problem for me. If the unit is still working this time next year I would give it a 5 star rating.
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Reviewed in the United States on November 25, 2024 by Jimfreex
Style: 18kW
Barely warm shower, water fluctuates from 95-103 when temp is all the way up at 140. Instal was easy but this is the first hot water I’ve had with the reno and wanted nothing more than to take a steamy shower. :(
Reviewed in the United States on March 26, 2025 by Amazon Customer Amazon Customer
Style: 6kW
This unit was easy to install and has worked perfectly since I installed it. I like the ability to adjust the temperature on the front panel. I have had 4 other units over the last four years and they all failed. We have hard water so that’s part of the problem. I haven’t checked the temperature at the faucet vs the temp setting at the unit but the hot water coming out of the faucet but it’s hot enough and stays at a pretty consistent temperature. For the price I could put in a new unit every year. Be sure you have 30 amp 220 volt power available near the unit. Requires a 30 amp double pole breaker in the supply panel. I recommend you have a power disconnect close to where you mount the water heater. I am feeding a laundry sink, a washer and an outdoor shower with unit. Very nice unit.
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Reviewed in the United States on August 21, 2024 by qwerty46