18kW Tankless Water Heater Electric 240V SIVUATEK, Self-Modulating Power for Optimal Efficiency, On Demand Instant Hot Water for Whole House, LED Display, ETL Certified
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Availability:
In Stock.
Arrives
Tuesday, Jul 21
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Model: TSB-180
Features
- PLEASE NOTE BEFORE PURCHASEEnsure this 18kW 240V tankless electric water heater meets your hot water demand. Requires 2 x 40-amp circuit breaker. Unit dimensions: 15.87"x11.14"x2.87"; standard 3/4" NPT water connection.
- ENERGY-SAVING & EFFICIENTEliminate standby energy loss with our electric tankless water heater no preheating, zero idle power use. Reduce your water heating costs by up to 60% compared to traditional models. Compact and space-saving, it installs flexibly under-sink or on-wall.
- INSTANT & POWERFUL HOT WATERWith 18kW of heating power and up to 99% thermal efficiency, this unit delivers endless hot water instantlyperfect for 34 simultaneous usage points such as kitchen and bathroom. No more waiting, just steady hot water when you need it.
- SMART TEMPERATURE CONTROLEquipped with an intuitive LED display you can easily set the desired water temperature from 86F to 131F in precise 1F increments. Once set, the system maintains a stable temperature output even with water pressure fluctuations.
- SAFE & RELIABLE OPERATIONBuilt with advanced water-electricity separation technology to prevent scale buildup and extend lifespan. Safety features include leakage protection, overheating protection, and auto shut-off, giving you peace of mind during every use.
Brand: SIVUATEK
Power Source: ac
Product Dimensions: 12.2"W x 17.26"H
Special Feature: Easy control, Intuitive display, Overheat Protection, Standard pipe fittings, Touch sensor
Color: Gray
Power Source: ac
Special Features: Easy control, Intuitive display, Overheat Protection, Standard pipe fittings, Touch sensor
Wattage: 18 KW
Voltage: 240 Volts
Maximum Temperature: 131 Degrees Fahrenheit
Heat Output: 131 Degrees Fahrenheit
Mount Type: Wall
Is Electric: Yes
Smart Home Compatibility: Not Smart Home Compatible
Item Dimensions W x H: 12.2"W x 17.26"H
Material Type: Aluminum, Brass, Metal
Brand Name: SIVUATEK
Model Number: TSB-180
Manufacturer: SIVUATEK Appliances
Included Components: 1 X 18kW Electric Tankless Water Heater;, 1 x Hardware Pack;, 1 x Installation Template;, 1 x User Manual & Warranty Card;
Unit Count: 1.0 Count
Color: Gray
Style Name: tankless
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Jul 21
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
Model: TSB-140
This product is AMAZING. The only thing you have to do is buy a 120V breaker, turn off the main breaker to the house, slap that 120v breaker into your breaker box (Yes, you can get slimline single-slot versions of these at the local hardware store (Lowes) for a few bucks to save space if your breaker box is crowded.), run 3 insulated copper wires about 1/8th of an inch thick from the Heater to your breaker positive, negative, and ground bar, unhook the Cold In and Hot Out hoses from your old water tank (With the water to your tank turned off of course - don't get doused!), and attach those to the hot and cold sides of your new heater. Turn the power and water back on, and select a temperature setting. Paid for itself in the first 2 months of use. Water comes out scalding hot, and I had to turn it down! This is in a 3 story house. Can take several seconds to push all the cold water out of the pipe and warm up, and a conventional tank is a few seconds quicker, but that's the ONLY downside. Another great upside is since it heats continuously on demand, you NEVER run out of hot water when showering or other heavy multi-person use. It's also way smaller than I thought, slim, sleek, and space-saving. Best $270 I ever spent. Told the gas company to go pleasure themselves with a barbed wire roll, and had my annoying, overly-priced monopoly-holding gas service (Dominion Hope) disconnected. One less bill to pay and utility to deal with - the electricity bill increase was barely noticeable next to the ridiculous monthly gas charges I was suffering. GET A TANKLESS HEATER IF YOU ARE A HOMEOWNER OR LANDLORD PROVIDING UTILITIES! The technology is here, works, saves space and time and money, you will not regret it. This model I personally vouch for after months of use.
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Reviewed in the United States on November 17, 2025 by Logan Bailey
Model: TSB-140
I've been using tankless units since 2017 (EcoSmart, made by Rheem). Compared to my previous experiences, this is a whole other level as far as temperature consistency, especially at higher flow rates. Before, I started out with a 55kW unit, which would maybe handle 0.5gpm with summer incoming water temps above 70°f. Come winter when the incoming water can drop down to 38°f, forget it. So, I kept the 55kW, and fed it into an 8kW unit of the same brand. That setup worked pretty well with those winter temps, at a flow of up to 1gpm, and I could turn the 55kW off for summer use, using only the 8kW unit. Then, the 55kW quit totally, and not long after, the 8kW started working when it wanted to. I would clean thing out with full strength cleaning vinegar and it would behave for a few days, maybe another month, then it was back to "surprise, its ice cold shower time again!". This 14kW unit has solved those issues brilliantly! I have it set to 101°f for showering so there's no energy waste adding cold water to the mix (no point to that like with tank style heaters). At 100/101°f, this unit stays in ECO mode (but not below oddly) and will deliver up to 2.5gpm up to 120° with incoming water at 58°f. So, no more "heyyy, whoaaaa BRRR" issues if my wife hits the kitchen sink while I'm in the shower, this thing delivers! A note on power consumption: specs state a max draw of 58 amps, but this has shown to pull about 61.8 amps when I really pushing it during install tests per my TRMS clamp meter. The 60 amp double pole breaker didn't trip, but I only held it at max flow and set to 131°f for a few seconds. Be sure and use 6AWG wire for the input, minding the run length as well (no more that 16 to 20 feet!!!). Consult wiring specs for amp draw and length of run if not having a professional do the install. Overall, its hyper simple to do yourself with minimal plumbing and electrical skills, but do follow code (its there for very important reasons folks). This states to NOT use a T&P relief valve, and TO install gate valves on the inlet AND outlet... none of which is typically recommended or allowed depending on local codes. I did install a T&P on the inlet, but didn't use gate valves at the inlet or outlet (already have one on the main inlet within 5 feet to start with). So far, this one is killing it after 2 weeks. Hopefully, you'll see the same results. Despite the temp ratings for central Texas not requiring a unit of this magnitude, it IS necessary with the lower incoming temps that come with even a mild winter where I live.
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Reviewed in the United States on January 15, 2026 by Texas Gonzo
Model: TSB-140
It was fairly DYI friendly to install and saved a ton of space in the bathroom allowing space for a tub. There were some slight hiccups in the beginning with some manufacturing flaws such as plastic up in the filter area preventing good water flow, but once I figured that out it has worked like a charm! It heats the water quickly and a month into use, I have had zero issues. It is a 4 star instead of 5 due to the beginning frustrations with plastic bits inside the unit.
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Reviewed in the United States on April 10, 2026 by Joan Thompson
Model: TSB-140
This thing doesn't take up much space and works pretty good. My water gets really hot at the sinks and the shower is pretty good also.
Reviewed in the United States on June 2, 2026 by Billy T.
Model: TSB-180
Work perfect on my duplex 1 shower and 5 faucets best decision I make
Reviewed in the United States on May 13, 2026 by Carlos R.
Model: TSB-180
Works great
Reviewed in the United States on May 9, 2026 by Greg Westbrook
Model: TSB-140
Tried three other brands from big box stores and had to return them because they did not work for the job needed. However this water heater was perfect andd I will be purchasing another 1.....maybe even 1 for the deer lease camphouse! Just perfect !
Reviewed in the United States on June 9, 2026 by Karla
Model: TSB-140
Looks great and installed nicely! Have not used it or turned it on yet. Still building little house .
Reviewed in the United States on June 17, 2026 by Leanna Denny