







Electric tankless water heaters require a large amount of electrical power (when running). Surprisingly so, they are very energy efficient and economic. We will look into exactly how much electricity does a tankless water heater use (by using the power equation P = I * V and cost equation Cost = kWh * t (h)).
Heating water is one of the most power-hungry processes. Tankless heaters heat up the water in seconds (5 seconds from cold to hot water). To achieve that, we need an incredible amount of electricity.
Does that mean that tankless heaters require a lot of electricity?
Yes and no. When they are ‘on’, electrical tankless heaters require up to 27,000W of electricity. For comparison, an average washing machine will require a bit more than 1,000W to run (and it will run for 1-2h). However, electric tankless water heaters are not running all the time. All this energy is used to heat up water only when we use hot water.
In fact, even according to the US Department Of Energy, tankless water heaters can significantly reduce monthly electricity bills:
“For homes that use 41 gallons or less of hot water daily, demand water heaters can be 24%–34% more energy efficient than conventional storage tank water heaters.” (DOE on energy efficiency of tankless water heaters)
Most households use less than 41 gallons of water per day. 24% – 34% is quite a lot of energy savings. Electricity-wise, tankless water heaters are a smart financial investment (they also last for 10-15 years).
But how can such a power-hungry appliance reduce the electricity bill?
It all comes down to how many amps does a tankless water heater draw (since the voltage is always the same: 220/240V). Let’s calculate a bit to see how much electricity does an on-demand tankless hot water heater use:
Calculating the maximum running costs of tankless water heaters is quite easy. The key information here is how many watts does a tankless water heater use. We’ll do one quick example here, with more to follow.
Example: You have a 20kW electric tankless heater. How much does it cost to run it?
Solution: 20 kW heater will spend 20 kWh worth of electricity if you run it for 1 hour. The average kWh price in the US is $0,1319. That means a 20kW tankless heater will spend, on average, 20 kWh x $0,1319 per kWh = $2,64 per running hour.
That doesn’t sound a lot, right? Obviously, there are many factors that come into play like intake water temperature, hot water demands, and so on. For a 20kW tankless water heater, the $2,64 per hour is the maximum electricity usage (running at 100% heating output). You will likely run your heater 100% output for the first 15 seconds, and then the heating output percentage (and hence water heater costs) drops.
Now, the real question is this:
How many hours per day do you run the tankless water heater? Here is how much it costs to run a 20kW electrical tankless heater from our example for different time periods:
* 20 kW running at 100% output for 10 minutes (shower): $0,66.
* 20 kW running at 100% output for 30 minutes: $1,32.
* 20 kW running at 100% output for 1 hour: $2,64.
* 20 kW running at 100% output for 2 hours: $5,28.
* 20 kW running at 100% output for 5 hours: $13,20.
Be aware that we always predispose:
1) Price of electricity to be $0,1319 per kilowatt-hour.
2) Power of heater is 20kW.
In this case you should replace the electricity price of your market and the power your purchased.
Is a tankless electric water heater for you?
What is a Tankless Electric Water Heater
Tankless electric water heaters take much less space than storage type as water was heated directly. When you turn on the hot water, cold water travels into the tankless water heater where it is heated by electric heating element. This allows you a constant supply of hot water.
For those large families who using a lot of hot water, install more than 1 heater is common. This will ensure non-stop hot water for showers, laundry and the dishwasher.
Advantages
Tankless electric water heaters (also called “on demand” units or an instant electric water heater) use 30 to 50% less electricity than tank type, saving about $100 or more per year, depending on water usage.
· Water was heated only when you turn on the faucet.
· The main advantage is that they eliminate the extra cost of keeping big volume of hot water in a storage tank, so you waste less energy.
· Continuously hot water supply, which is ideal for filling a big hot tub.
· Much more compact than a standard water heater and mount on a wall.
Electric vs Gas Tankless Water Heaters
The biggest difference between electric type and gas type is their efficiency. Electric tankless water heaters are typically around 98% or more efficient while gas type is around 80-85% efficient.
Tankless water heaters will free up space that a bulky water heater typically occupies.
The Bottom Line: Pricing and Installation
When you’re pricing a unit, be sure to get an estimate or firm bid on installation costs. This is not a do-it yourself project unless you have pro-level skills. You can contact us (JNOD) for more professional instructions.
Figure A: Tankless Water Heater Details
When a hot water tap is opened, the heating elements turn on. Water is heated as it flows through the heating element.
Yes, but a tankless water heater does more than save you money.
Savings: Space
Since tankless water heaters do not have tanks, they take up less space. You don’t need to have a utility room or area in the garage for your water heater. Your tankless water heater can be stored in a closet or under the sink. Extra space is valuable these days, especially if you’re living in a smaller home or condo.
Savings: Energy
Traditional water heaters hold around 30-50 gallons of water and keep it heated until you’re ready to use it. Depending on the size of your family and the amount of water your family uses, this could be costly. (Did you know that water heater energy usage is the second-highest source of energy use in the average home?) Tankless water heaters don’t hold water, so they heat the water as it comes in—no constant energy to keep 15 milk jugs’ worth of water hot.
Savings: Time
Tankless water heaters save you time in the morning because the water is heated as it comes through until you are finished. While a traditional tank does have hot water on demand, that’s only until the tank runs out. Then you have to wait for the tank to refill and warm up the water. Tankless heaters don’t have that lag time because there’s unending water flow from the tank to the tap.
Savings: Money
Most new homes have a traditional water heater already installed when you move in. If you’re looking to replace the traditional tank, however, there is some work required. While installing a tankless heater might present a higher price tag than expected, the overall financial gains will overcome that deficit. It will raise the initial investment, but it’s an investment worth looking into for your home and your family. When comparing the overall savings of space, energy, time, and money – the savings really can add up.
We are a professional manufacturer of instant electric water heater and electric water tap, which is located in Shunde, the hometown of producing electric appliances. We are a set of manufacture, research and development, marketing integrated company.
We introduced a series of advanced production and detection facilities since foundation, with annual production capacity of million sets, the products are exported to north and south America, Europe, and other countries all over the world. Owning the best OEM and ODM exportation, technology and quality, we have become one of the most professional manufacturers of instant electric water heater and electric water tap in China.
JNOD insisted on developing with technology innovation, we possessed of several national famous technicians and had invented multiply product patents. We strictly implemented the ISO international quality management system, produced all the main parts and components independently, and the products passed the CCC, CB, CE, ETL(UL standard) certification with reliable guaranteed quality. In October 2021, JNOD Testing Centre achieved CNAS accrditation, being recognized by the National Laboratory, becoming one of the first enterprises with national accreditation laboratory qualifications in the electric water heater industry.
Our sales team have extensive experience of oversea markets.
We provide sincere and professional services, including OEM/ODM services, technology support, market analysis, usage of design and composition of installation. We have succeeded in providing marketing consultancy services and business solutions for our customers from over 50 countries. With tailor-make solution of hot water supply base on customers market demand, we helped many customers obtain great sales performance and were highly regarded.
Make the worlds best products, create the international top brands are the pursuit and dream of JNOD.
Let’s look forward to the future, we sincerely invite you to cooperate with us and achieve win-win together for a better tomorrow.
ODM
Major in providing required products for the customers with our strong capability of research and development on ODM basis.
OEM
Achieve customer’s own idea and design for the products and mass production.
JNOD BRAND
JNOD do self-owned brand in China domestic and the oversea market, in addition, we have authorized brand agent in Argentina.
What's the best moment of the day? The answer is to take a bath. You can wash away the tiredness and feel clean and comfortable.
You probably do not give your water heater much thought most of the time . After all, if a home appliance is performing its intended function, it will eventually become invisible.
If you want to enjoy a hot bath without hindrance, I would highly recommend using tankless electric water heater. Hot water is always available, no waiting, and no need to preheating .
You many have a question: Do tankless water heaters use more water than traditional tank water heaters? The answer is : NO . Tankless electric water heaters heat water as needed rather than keeping it in a tank until it is needed. A traditional water heater must constantly turn on and off to keep water warm and ready to go because once water sits in a tank, it starts to lose heat. Water is more energy- efficient and water save with tankless because it is heated quickly and only when necessary.
JNOD tankless electric water heater with up to 97% high efficiency,no need to preheating and can save water perfectly . You don't need to worry about wasting water when you take a bath . Perfect bathing experience.
Now a day, tankless electric water heaters are getting better and better, it is a very wise choice for people saving energy bills, approve their financial status. Especially those using JNOD patent cast aluminum heating element, up to 97% heating efficiency will better save much more money than others.
Not decide yet? Then, take a look to below pros of tankless electric water heaters, it will help on the decision making.
Pro #1: Instant Endless Hot Water
Tankless water heaters can provide unending stream of hot water almost instantly. It supplies hot water within 3 seconds without the inconvenience of bulky storage tanks.
Pro #2: Longer Lifespan
For using our patent heating element, structure itself could anti-limescale, the element will not have limescale inside, even in very hard water area, it could still work at least 5-8 years, some even could last longer, like 10 years!
Pro #3: Cut Off “Standby Loss”
Unlike the storage heater, tankless type will only consume electricity when user open the valve, and heating efficiency of our heating is 97%, minimized energy loss, saving energy paid every day.
Pro #4: Space Savings
Tankless electric water heaters are much smaller than bulky storage models, even smaller than gas water heater. Installers usually mount them on a wall in an inconspicuous place in the basement. In smaller homes, the space savings is a welcome benefit.
When it comes to tankless electric water heater, one of the biggest mistakes is buying a unit that is too weak to satisfy whole house hot water needs.
You don’t want one that is too small to supply whole house hot water needs, nor too big that power cord could not support the amperage when the instant electric water heater works.
The power of tankless water heater should be as appropriate to your household hot water needs as possible.
How many kW for JNOD tankless electric water heater?
To properly answer which power do you need, you have to figure out below points beforehand:
1. How’s the temperature of inlet water at coldest time?
2. How many degrees could the certain heater heat up at how much water per minute?
Example:
If inlet water flow has 2L/min, max temperature rise of a 5kW model could be up to max. 35℃, But in the relatively cold area, winter time the coldest water temperature is 0℃, plus 35℃, it could only reach 35℃, even it works with full power, there still not hot enough for shower use.
But for the warmer area, in winter, inlet water still have 12℃, then total it could heat up to 47℃, it was quite good enough for your shower use.
In JNOD, we have a professional team to help you choose models with a most suitable power, no matter for single shower use or multiple points use, we will help to fulfill your different hot water requirement!
The 15th day of lunar August month is the full moon night in of the lunar month, so the 15th d is called the " Mid-Autumn Festival”. Friends and relatives will send moon cakes, melons and fruits to each other, which means "family reunion" and "good luck and peace", we also called "reunion festival".
On the night of the 15th day of the lunar August month, eat moon cakes, drink Chinese tea, and watch the moon together the families are our traditional celebrating way.
In order to celebrate this festival, JNOD will be on holiday from 09/10-09/12, and our company's employees to reunite with their families and enjoy the family time together. if you have questions, please leave the message to us and we will reply soon.
Let us enjoy good time together.
A hot shower or bath is one of life’s little but most precious pleasures. And so, if you’re building a tiny house, you need a reliable water heater. But how to choose the best water heater for your tiny bathroom?
We’ve compiled a list of the best tiny house tankless electric water heaters from JNOD product catalogue today, according to user reviews, personal experiences, and top selling units.
1. Wide Applicability FE-T Model
FE-T 240V Instant Electric Water Heater is the perfect no-nonsense water heater for tiny house homeowners just looking for that simple, affordable solution. Several powers to your choices: 3.5/4.5/5.5/7/9/11/13.5kW, so you can find one to works for your home.
With an installation time of just one hour and a maximum flow of 7L/min, FE-T is also quite smart to adjust and operate with its touch key or WIFI function.
2. Super MINI KF Model
At just 2.9kg and tucked into such a compact frame, KF Electric Tankless Water Heater can be installed almost anywhere you might want, which is perfect for the size limitations of tiny homes. The small size also means that installation is simple and straightforward, so anyone who can read the instructions can safely install this in their home in no time at all. No need to call in a professional to install to help you heat water.
KF tankless hot water heater is often described as the best tankless water heater for tiny homes. Its compact shape means you can easily install it near its point of use, and in just 15 seconds you can enjoy hot water flowing. But the powers to select are 3.5/5.5/7kW, So it is also ideal for sinks and low-flow showers.
When buying a tankless water heater, most people don’t know what size tankless water heater they need.
If you are looking to install tankless electric water heater and you’re unsure of which size you should buy, here are some factors you should take into account:
- The size of your house
- Flow Rate (GPM): How much hot water you will need at any given time
- Temperature Rise (ΔT): The difference between the incoming cold water temperature and the desired temperature
Your Household Size
If water heater is too small, it will result in it not being able to produce enough hot water for your household demand. For example, you might not be able to run more than one shower at a time, especially in the freezing winter.
On the other hand, water heater is too large, it will end up being more costly than necessary, since you will be paying more upfront for the larger size (although it could be useful if you plan to upsize your home later).
Hence, to work properly, a tankless water heater needs to be just the right size to meet your home's hot water demand.
Rate of Water Flow
Tankless water heaters are often referred to as demand water heaters. On-demand refers to having continuous hot water output for as long as the hot water tap is open. However, having multiple hot water taps open together will reduce the hot water output. Having too many hot water taps open at once will produce lukewarm water if the tankless water heater’s output capacity is exceeded.
To help you estimate the flow rates of most of your faucets, we shared some typical flow rates below. The actual flow rates may be different for your house and different appliances.
Temperature Rise
After you have calculated the flow rate of every faucet in your house, you must now determine how much heat your heater needs to generate to give you the required heat in your water outlets. We’ll take into consideration the temperature of the water that flows into your home and the temperature of the water that you want to flow out of your tap to determine the required temperature rise.
You might still have some questions relating to the size of instant electric water heater you need, please let us know in the comments below.