- 1 Electric Tankless Water Heater Reviews – Updated List
- 1.1 1. Stiebel Eltron Tempra Plus 24 Tankless Electric Water Heater
- 1.2 2 . EcoSmart ECO 27 Tankless Electric Water Heater
- 1.3 3 . Rheem RTEX-13 Tankless Electric Water Heater
- 1.4 4 . Titan SCR2 N-120 Tankless Electric Water Heater
- 1.5 5 . Sio Green IR30 POU Tankless Electric Water Heater
- 1.6 6 . Stiebel Eltron DHC 3-1 Tankless Electric Water Heater
- 1.7 7 . Bosch Electric Tronic 3000 US12 Tankless Electric Water Heater
- 1.8 8 . Atmor AT-D18TP-AZ Thermopro Tankless Electric Water Heater
- 1.9 9 . Ecosmart POU 3.5 Tankless Electric Water Heater
- 1.10 10 . Marey ECO180 Tankless Electric Water Heater
- 2 Terms to know:
- 3 4 Main Reasons to Go Tankless:
- 4 Types of tankless water heaters:
- 5 How do electric tankless water heaters work?
- 6 Installation:
- 7 Maintenance:
- 8 Electric Tankless Water Heater Buying Guide:
- 9 Best Electric Tankless Water Heaters Comparison Chart
- 10 Conclusion:
If you do not want to have to wait for hot water, to have the hot water run out during your shower and to pay a lot for this, then you must be looking for a tankless water heater.
A tankless, or on-demand, water heater only heats water when you need it, avoiding any standby energy losses. Despite their initial purchase and set up expenses, these heaters provide you with an endless source of hot water, saving money on energy costs and paying for themselves over a short time.
In addition to freeing you from a tank size and the energy consumption of heating and reheating the same tank of water, electric tankless water heaters also offer clean and fresh water at all times. For the very same reasons, they can practically be installed on any wall, thus saving you a lot of space.
When considering all the benefits listed above, a tankless water heater is supposed to make your life a lot easier. However, due to the vast variety of choices, including electric or gas, you will find out that the search for the right product is quite difficult. The good news is, we have already done all the research for you! For a conscious decision when purchasing the best electric tankless water heater, all you have to do is go over our well-analyzed reviews.
- Stiebel Eltron Tempra Plus 24 Tankless Electric Water Heater
- PRICE $$$$$
- Dimensions : 21 x 19 x 8.5"
- Weight : 20 pounds
- Energy Savings : 15 to 20%
- Maximum Water Flow Rate : 5.5 GPM
- Temperature : up to 140°F
- EcoSmart ECO 27 Tankless Electric Water Heater
- PRICE $$$$
- Dimensions : 3.6 x 17 x 17"
- Weight : 16.8 pounds
- Energy Savings : up to 50%
- Maximum Water Flow Rate : 6 GPM
- Temperature : 80°F to 140°F
- Rheem RTEX-13 Tankless Electric Water Heater
- PRICE $$$
- Dimensions : 4 x 9 x 13"
- Weight : 4 pounds
- Energy Savings : 8 %
- Maximum Water Flow Rate : 3.2 GPM
- Temperature : 80°F to 140°F
- Titan SCR2 N-120 Tankless Electric Water Heater
- PRICE $$$
- Dimensions : 12 x 10 x 5"
- Weight : 2 pounds
- Energy Savings : 40 %
- Maximum Water Flow Rate : 4 GPM
- Temperature : above 65°F
- Sio Green IR30 POU Tankless Electric Water Heater
- PRICE $$
- Dimensions : 13.5 x 8.5 x 3"
- Weight : 6.4 pounds
- Energy Savings : up to 20 %
- Maximum Water Flow Rate : 1 GPM
- Temperature : Variable
Electric Tankless Water Heater Reviews – Updated List
1. Stiebel Eltron Tempra Plus 24 Tankless Electric Water Heater
Stiebel Eltron Tempra 24 Plus is a tankless electric water heater that has been designed for a greater user experience. Its advanced temperature control system combined with a digital display ensures no more cold water surprises. This advanced system controls the water flow to meet the demand as it keeps the temperature constant. Also, with the help of the digital display, you can set the temperature to whatever degree you wish, up to 140°F.
Stiebel Eltron Tempra 24 Plus is only about the size of a briefcase and its sleek design will fit almost anywhere. Furthermore, it does not require venting which means you can install it wherever you want, inside or outside your home!
In addition to all these advantages, this product enhances its worth with an impressive energy-saving performance. It has a maximum GPM rate of 4.0 which gives you the power to provide hot water for two fixtures at once. If you are living in a house of up to two bathrooms and want to enjoy long hot showers, Stiebel Eltron Tempra 24 Plus is just for you.
2 . EcoSmart ECO 27 Tankless Electric Water Heater
EcoSmart ECO 27 is a tankless electric water heater that has been developed using the most advanced technologies available for water heating systems. This product regulates the exact amount of energy to heat the exact amount of hot water needed by using its self-modulating technology, thus saving you up to 50% on your water heating costs. Also, ECO 27 has a digital control panel that gives you easy and precise control over the temperature of the water output.
Aside from saving you money, EcoSmart ECO 27 saves you a lot of space thanks to its compact and wall-mounted design. Measuring 18 x 17 x 3.75 inches and weighing 13.75 pounds it can be fit into very tight spaces.
EcoSmart ECO 27 has been configured to accommodate colder climates where the water temperature can reach as low as 37°F. At this temperature, it can heat almost 3 gallons of water per minute. If you are living in a two bathroom house, we can easily say that two showers can be run simultaneously without running out of cold water.
To top it off, we must mention that ECO 27 has a lifetime warranty, showing how much the manufacturer trusts its product. If you do not ever want to worry about competing with family members to be the first to take a shower, consider having a closer look at this great unit.
3 . Rheem RTEX-13 Tankless Electric Water Heater
Rheem RTEX-13 is the descendant of RTE-13, which has been one of the most popular electric tankless water heaters on the market. This updated version is just as effective and is even better in many ways!
Rheem RTEX-13 is perfect for you if you are living alone in a studio apartment or in a small apartment with one roommate. It is a very compact unit that can fit into cramped spaces easily. You can install it directly under your sink and won’t even know that it is there. In spite of its small size, RTEX-13 is a beast with a flow rate of 3.2 GPM. At this flow rate, you can take a shower while your roommate rinses the dishes.
For a small house without a tremendous need for hot water, we do not think that it gets any better than Rheem RTEX-13!
4 . Titan SCR2 N-120 Tankless Electric Water Heater
If you are living in a place with a warmer climate like Florida or Texas, Titan SCR2 N-120 might be just what you need for a whole house electric water heating system. With its flow rate of 4 GPM, it is perfect for medium-sized houses with one or two washrooms.
Titan SCR2 N-120 utilizes a self-modulating flow sensor technology that enables you to reduce your energy consumption 50 times when compared to traditional water heaters. Its digital display makes it very easy for you to adjust the temperature of the water to the desired levels.
One of the much-liked characteristics of Titan SCR2 N-120 becomes handy if you are living in a region where your water condition is not favorable and is considered as hard water. Many brands are not very efficient in overcoming this problem of lime and sediment buildup but Titan SCR2 N-120 has a good reputation for reducing it remarkably.
In addition to all these, Titan SCR2 N-120 offers a 10-year warranty on water carrying components and 1 year on other components, which makes it a good deal in the long run.
5 . Sio Green IR30 POU Tankless Electric Water Heater
Does your kitchen sink water never get hot enough? Does your sink in the office toilet need hot water? Sio Green IR30 might be just what you need!
Sio Green IR30 is a point of use portable water heater which uses the latest technology of quartz infrared energy to provide instant hot water. It uses low amperage while maintaining a higher water flow capacity. Meanwhile, it decreases your energy cost by up to 65% when compared to other electric tankless water heaters on the market. It can provide you with continuous hot water using a regular household voltage of 110V at a 1 GPM flow rate. Moreover, this unit comes with a 2 years pro-rated warranty!
Sio Green IR30 offers you easy installation, maintenance-free operation, superior heating efficiency, and reduced electricity bills. If you are looking for a water heater for hand wash applications only, do not lose any more time before you have a closer look at this great unit!
- Stiebel Eltron DHC 3-1 Tankless Electric Water Heater
- PRICE $$
- Dimensions : 18.9 x 7.9 x 14.2"
- Weight : 4.6 pounds
- Energy Savings : Up to 50 %
- Maximum Water Flow Rate : 0.5 GPM
- Temperature : up to 40°F
- Bosch Electric Tronic 3000 US12 Tankless Electric Water Heater
- PRICE $$
- Dimensions : 12.2 x 3 x 6.5"
- Weight : 4.9 pounds
- Energy Savings : up to 30%
- Maximum Water Flow Rate : 1.8 GPM
- Temperature : 45°F to 75°F
- Atmor AT-D18TP-AZ Thermopro Tankless Electric Water Heater
- PRICE $$$
- Dimensions : 17.4 x 5.2 x 13.4"
- Weight : 17 pounds
- Energy Savings : up to 50 %
- Maximum Water Flow Rate : 3.7 GPM
- Temperature : 90°F to 135°F
- Ecosmart POU 3.5 Tankless Electric Water Heater
- PRICE $
- Dimensions : 3 x 11 x 6"
- Weight : 4 pounds
- Energy Savings : 60 %
- Maximum Water Flow Rate : 0.5 GPM
- Temperature : 37°F to 77°F
- Marey ECO180 Tankless Electric Water Heater
- PRICE $$$
- Dimensions : 11 x 3.5 x 16.1"
- Weight : 18 pounds
- Energy Savings : 60 %
- Maximum Water Flow Rate : 5 GPM
- Temperature : 36°F to 80°F
6 . Stiebel Eltron DHC 3-1 Tankless Electric Water Heater
Stiebel Eltron DHC 3-1 is a well-constructed, economical and super-compact electric water heater designed for basic point of use applications with relatively constant flow rate demands. In other words, if you need hot water for your commercial washroom or kitchen sink or a small outdoor shower, you should definitely have a look into this model.
Stiebel Eltron DHC 3-1 is one of the very few tankless water heaters available that can be run on 120 (110) volt power. It is very energy efficient thanks to its sophisticated water flow sensor eliminating all standby energy losses. Also, it comes with a scald-guard thermostat and thermal hi-limit cut-out switch, which keep the water temperature within safe limits at all times.
Stiebel Eltron DHC 3-1 is very small in size and will conveniently fit directly under your sink or inside a small cupboard nearby. Moreover, it is extremely easy to assemble. If endless hot water running through one faucet attracts your attention we highly suggest that you consider this smart product.
7 . Bosch Electric Tronic 3000 US12 Tankless Electric Water Heater
Are you looking for a budget-friendly and simple water heater for a point of use application such as your garage sink or attic wet bar? In this case, Bosch Electric Tronic 3000 US12 tankless water heater is a perfect choice.
The unit runs at 98% thermal efficiency with a flow rate of 1.1 GPM to 1.8 GPM, depending on the outside temperature. Tronic 3000 makes sure that standby energy loss is minimal. It also features on-unit thermostatic control that enables you to set the water temperature to your desired range.
Bosch Electric comes with a sleek design that allows it to be installed singly under your sink or as a pair with the entire home sink system. Moreover, it is so compact and lightweight that it can be mounted on a wall in any direction which makes it a great choice for a variety of spaces.
To top it off, Bosch Electric is backed up by a 5-year warranty on its heating element and 1-year warranty on its other components. We must mention that both these warranties are limited, though. If you do not want to miss this good catch give a chance to Bosch Electric Tronic 3000!
8 . Atmor AT-D18TP-AZ Thermopro Tankless Electric Water Heater
If you want to get a high-quality water heater below average price, you should definitely look into Atmor AT-D18TP-AZ Thermopro electric tankless water heater. Atmor’s product attracts our attention primarily with its IP54 certification, showing how much this heater values our safety. This certificate suggests that the unit is splash safe and can be installed near sinks and showers.
Atmor Thermopro is perfect for moderate to warmer climates. It can heat 3.7 gallons of water per minute on average, which makes it ideal for an apartment of a small house. However, this heater is also equipped for temperatures as low as 37°F. At colder climates, the flow rate drops to about 1.9 GPM, though.
Atmor’s digital control allows you to set temperature in increments of 1°F and its compact design saves you a lot of space. Another space saver with this water heater is that there is no need for venting, so you can practically install it anywhere, inside or outside.
Last but not the least, Atmor Thermopro has a 7 years warranty against leakage and 2 years warranty covering parts. Check all the details in our detailed review and get ready for long, hot showers!
9 . Ecosmart POU 3.5 Tankless Electric Water Heater
Ecosmart POU 3.5 electric tankless water heater is a true point of use model because it is specifically designed for single applications with a maximum flow rate of 0.5 gallons per minute. It works perfectly for a single sink at a time where the inlet temperature is above 57°F. At this inlet temperature, the ECO POU 3.5 can heat 0.5 gallons per minute to 105°F.
Due to its extremely compact size, POU 3.5 fits under sinks and eliminates long pipe runs so you won’t have to wait for endless, hot water. If you verify this model is the right size for the expected demand, we strongly believe that you will be satisfied with Ecosmart POU 3.5’s performance.
If you own a boat or an RV, or if you just need hot water in your garage, do not skip to check our detailed review of Ecosmart POU 3.5!
10 . Marey ECO180 Tankless Electric Water Heater
Marey ECO180, a part of Marey’s Eco line, utilizes SMART technology as the rest of the products in this line. But what does this SMART mean what’s its use? Well, if you are looking for a water heater with maximum energy efficiency, SMART is actually the remedy. Through this technology, a few simple adjustments on an LCD Panel allows you to program the exact desired water temperature thereby optimizing electricity consumption.
ECO180 is a multiple point of use device but its performance may vary depending on the climate. To put it roughly, if you are living in a region with a mild climate, this unit can provide 36°F increase at 4.0 GPM, allowing you to take a shower while the dishwasher is running. However, if you are living in a colder region, it can provide you with up to 80°F at 1.5 GPM for hot water output at one point of use at a time.
Moreover, ECO180 is designed with corrosion-resistant elements that reduce hard water buildup and is 100% non-corrosive. Besides all that, Marey ECO180 has a 5 years warranty and to make it even better a very good post-sales service.
Terms to know:
- Flow rate: Amount of water moving through a pipe or channel within a given or standard period, usually a minute or hour.
- GPM: Stands for gallons per minute. It is used to measure the flow rate.
- Efficiency: It is a level of performance that uses the lowest amount of inputs to create the greatest amount of outputs. In our case, the input is the energy used by the water heater and the output is the amount of heated water.
- EF: Stands for energy factor. It is used to measure efficiency.
- BTU: Stands for British thermal unit. It is the amount of heat needed to raise 1 pound of water temperature by 1 degree Fahrenheit.
4 Main Reasons to Go Tankless:
Endless Hot Water:
A conventional tank water heater stores constantly heated water inside its tank, which at most has a capacity of keeping approximately 80 gallons of water. You use this water for cleaning, cooking, bathing, washing the dishes and so on. When you do some of these chores at the same time, it is very probable that you will eventually run out of hot water. However, a tankless water heater heats cold water as it passes through the unit. That is why they are also called on-demand water heaters; they only heat water when you need it and as much as you need, providing you with a continuous and unlimited source of hot water.
As you can tell by the name, a tankless water heater comes without a tank and thus saves you a lot of floor space. A conventional water heater has a bulky tank to store water which takes up a lot of space in your basement, garage or in a large closet. However, a tankless water heater can be mounted on a wall or under your sink taking up almost no square footage at all. Also, storage tank water heaters cannot be placed outdoors whereas some of the tankless water heaters can.
The efficiency of a water heater is rated according to its energy factor, EF, which is the ratio of the energy used by the water heater to the amount of hot water provided by this heater. Tank water heaters are lower in efficiency because they constantly use energy to heat and reheat the same water in their tank to keep it ready for a time of need. Also, they constantly lose heat to the environment as the water is stored in a large tank. Tankless water heaters avoid this standby energy loss since they produce hot water only when needed.
Tank water heaters last approximately 10 to 15 years whereas tankless water heaters have a longer lifespan of 20 years or more. This means that with tank water heaters there is more turnover and you have to replace them almost twice as tankless heaters.
Types of tankless water heaters:
Electric Tankless Water Heaters:
These water heaters run on electricity. In other words, they use electric power to heat water.
Electric water heater flow rates vary from about 1.2 to 6 GPM. Point-of-use models, such as those that provide hot water for a single sink, are rated 1.2 GPM. A 2.6 GPM heater has a heating capacity for one shower at a time, whereas a 4 GPM water heater one shower and one sink, and a 6-GPM two showers. Even though it may vary depending on the size and model of the product, electric water heaters have a heating capacity of 4GPM on average. Therefore, they are good for point of use applications such as garage sink or for small to medium sized apartments rather than for higher use households.
Manufacturers of electric tankless water heaters claim to reduce heating costs in a range of 30 to 60 percent. They have energy factors (EF) ranging from 0.75 to 0.99, which is 0.5 to 0.7 for conventional water heaters.
Gas Tankless Water Heaters:
These water heaters heat water by using gas as power. Gas water heater flow rates vary from 1.3 GPM to 11 GPM which make them fit for whole house systems in colder climates and crowded families with a lot of hot water demand.
Gas tankless water heaters are said to reduce energy costs from 20 to 25 percent. Also, they have energy factors (EF) in the range of 0.7 to 0.85
There are two types of gas tankless water heaters, the ones that run on natural gas and the ones that run on propane. Their working principle is more or less the same but you may check xxx for more details.
How do electric tankless water heaters work?
Tankless water heaters, also known as demand-type or instantaneous water heaters, work by using heating elements which are activated by the flow of water when there is a demand for hot water. Water is heated instantly as it flows through the heater and is not stored in anticipation of demand. So, there is no storage tank and the term “tankless” comes from this fact.
When you turn on a hot water tap, cold water travels into the electric water heater through an inlet pipe. Inside the unit, there are some coils designed to heat water as it flows through. When hot water is requested, an electric current is applied to these coils to provide them with the power to heat the water passing through the vessel.
To sum it all up:
- A hot water tap is turned on.
- Water enters the tankless heater unit.
- The flow sensor detects water flow.
- When the required flow rate is reached, control ignites the burner.
- Water circulates through the heating element.
- The heating element heats water to the designated temperature.
- When the tap is turned off, the unit shuts off.
It is important to keep in mind that when the flow rate of hot water increases, the heater’s performance of raising the water temperature decreases and vice versa. For example, if the demanded flow rate of heated water is 1 GPM, then the unit may be able to increase the temperature of incoming water by 100oF. However, if the flow rate demand increases to 4 GPM, then the unit’s ability to increase the temperature will drop to 50oF.
As mentioned above, the flow rate affects the temperature of water generated by the heater. So, if you are living in a region where incoming water pressure unpredictably changes, the water temperature may fluctuate uncomfortably. In order to avoid this, in most of the units, there are some microprocessors to maintain a constant water output temperature. The temperature is kept at the requested level even at varying flow rates through these microprocessors. You simply set the desired outlet water temperature and regardless of the flow rate, the unit will maintain this temperature by modulating its heating elements accordingly. Some units adjust the water flow rate themselves to keep the water temperature at the desired level.
Also, both electric and gas tankless water heaters have a threshold for a minimum flow rate, under which they will not be activated to generate hot water. For instance, if a sink draws maximum 0.5 GPM of water and the tankless water heater has a minimum of 0.6 GPM flow rate requirement, there will be no hot water supplied to this sink because the unit will not be activated at this rate. Different manufacturers have different flow detection technologies and applications to achieve this. It is important to note that electric tankless water heaters in the market today mostly have lower minimum flow rate requirements than gas water heaters.
Installation of a conventional electric tank water heater needs enough space for the entire tank water heater unit. Since they do not have a bulky tank, electric tankless water heaters require much less space for installation. Moreover, unlike gas water heaters they have the advantage of not requiring air for combustion or flue exhaust. Therefore, electric tankless heaters can be practically installed anywhere; indoors, outdoors or any space for point of use applications.
To heat water flowing at one gallon per minute by 1oF, you approximately need 147 W of electricity. According to this fact, we can say that electric tankless water heaters draw quite a lot of energy. For example, a conventional electric storage water heater requires no more than 5 kW of electricity to operate. However, this value is in the range of 2.5 kW to 28kW for electric tankless water heaters, depending on the size of the unit. So, in terms of voltage, smaller units need 120 volts while larger units need 240 volts of current. These electrical requirements need an electric service that can supply a large amount of current, which is not the case in most of the houses. Thus, installing an electric tankless water heater will probably require an upgrade in the electric service of the house.
Mostly, older homes have an electric service capacity of 100 amperes and newer homes around 200 amperes. When it is considered that electric tankless water heaters can draw up to between 120 – 160 amperes of electricity, these service capacities will be inadequate. Even newer homes of 200 amperes will require an upgrade due to the fact that they will only have 80 to 40 amperes left for other electrical devices.
An upgrade to a home’s electric service may involve the following:
- Changing to heavier gauge wires
- Installing a circuit breaker fit for higher electric current draw
- A larger meter loop
- A new and larger main panel
Proper installation of a unit depends on many factors which include;
- fuel type
- local building code requirements
- safety issues
Hence, it may be best to have a qualified plumbing and heating contractor to install your water heater. If you are determined to install the unit yourself, then it may be a good idea to consult the manufacturer first and follow the necessary installation and instruction manuals. Remember that the wrong installation will jeopardize the warranty of the device.
Once you have checked everything stated above and are ready for installation, follow the steps listed below to install your brand new electric water heater:
- Turn off the main incoming water line to the house.
- Disconnect the supply line from the old water heater. In case there is some water left in the line, place a bucket underneath the supply line to avoid any spills on the floor.
- Disconnect heat source from old water heater by unplugging the appliance from the wall outlet.
- Once you have removed your old water heater, make sure that you dispose of it according to the laws in your residence area.
- Mount your new electric tankless heater on a wall according to manufacturer’s instructions making sure that its weight is being supported.
- Hook up the connection for the supply (water) line.
- Plug the heater into the wall.
- You are set to go for a warm shower!
The main factor affecting the life of a water heater is the accumulation of minerals such as calcium inside the unit. Especially if the water in your region is considered as hard water, which means that it is rich in calcium and limestone, these residues will accumulate on the heating element over time and unless cleaned, they are very likely to cause damage to the unit. Moreover, the buildup of these deposits will also decrease the efficiency of your tankless heater.
Manufacturers suggest performing active treatment on your unit regularly before calcification causes any malfunctioning or irreparable damage. This treatment, also referred to as “decalcification”, basically includes the following steps:
- Remove the cover plate exposing the power source and shut off valves and water source connections. Refer to your owner’s manual for identification.
- Shut off all lines and water inlet and outlet sources. You may have a system containing two sources of power, one for the heating element and the other for the control panel. Be sure to turn off both.
- Release all water pressure by opening the overflow valve. Refer to the owner’s manual to identify.
- Place a sump pump of 1/6th horsepower in a 5-gallon bucket. Connect a small hose to the output connection of the sump pump and connect the other end to the input connection on the tankless heater.
- Connect another small hose to the output side of the heater. Let the other end rest open in the 5-gallon bucket.
- Add 2 to 3 gallons of white vinegar and 1 gallon of water to the sump pump bucket. Make sure the pump is submerged in the vinegar/water mix and that the output heater hose will run back into the bucket.
- Start the pump and allow the vinegar to cycle through for 45 minutes. This process will remove the lime and calcium, freeing up your system to run like new again.
- Refer to the manufacturer’s manual of your tankless water heater for exact instructions on how to safely re-start your water heater.
You can do this decalcification process yourself or call a professional to do it. Of course hiring a professional is easier but on the other hand, doing it by yourself will save you money. How often you should perform this treatment depends on the water hardness in your region. You may refer to a hard water map provided by the government to check the hard water concentration in your area. With lower water hardness levels, annual maintenance is considered sufficient but if you live in an area with hard water your tankless water heater may need to be descaled every six months instead.
Remember that periodic maintenance of your tankless water heater can significantly extend its life and minimize loss of efficiency. Please read your owner’s manual for other specific maintenance recommendations.
Electric Tankless Water Heater Buying Guide:
When selecting the type and model of the water heater best fit for your needs, we highly recommend that you consider the following:
- Energy source & availability: The energy source you use for water heating will not only affect its annual operation costs but also its efficiency.
- Size: To provide your household with sufficient hot water and to maximize efficiency, you need a properly sized water heater.
- Energy efficiency: To maximize your energy and cost savings, you should check how energy efficient a water heater is.
- Costs: Operating and maintenance costs are also important if you do not want any surprises after your purchase.
- Warranty: Different brands and models have different warranty coverages. It is important to choose a brand that stands behind its product.
The Right Energy Source:
Electric tankless water heaters place a load on the electric system of a house. Most houses have 100 to 200 amp electric service. Depending on the electric use of the household, you may get away with a point of use electric tankless water heater or a small whole house unit without having to upgrade the electric service of your home. But for larger units make sure you go through all the checkpoints listed below:
- Almost all electric tankless water heating units require at least a new breaker or two and a new wire. People with some electrical experience may be able to do these simple upgrades themselves, saving some money. However, if you do not have the experience you will have to call for an electrician.
- If your breaker panel is already filled up you will need to install a new panel for the water heater unit. This will lead to an additional cost and you will need to hire a professional to set it up.
- If your home’s electric service is not sufficient to accommodate the new electric water heater, then you will need to upgrade it or add a second service. It may be wise to check how much this upgrade will cost you before making a purchase.
In case you are not familiar with the electrical system of your house or how much demand is already placed on it, you may consult an electrician.
The Right Size:
When looking for a tankless water heater, the first thing you should decide on is if you will use the unit for the whole house or only as a point of use application;
- Point of use installation: In this case, a water heater provides hot water only for one device such as a sink. Purchasing a point of use electric tankless water heater is a very good idea if you need hot water for one fixture only. Since they are very small in size, they can be placed right under or next to the fixture that it will be used for. This close proximity eliminates the waiting time for hot water to arrive at the fixture and also the heat loss that occurs when water travels long distances through pipes. Moreover, you save up a lot of space.
- Whole house installation: In this case, a water heater covers the hot water requirement for an entire house. If you need your water heater to provide hot water for the whole house, check below for tips to choose the right one.
The flow rate:
Check the number of devices you want to run simultaneously; like how many showers, how many sinks. All these devices have their own flow rates in gallons per minute, add them up and you will find out the flow rate you expect from your tankless water heater.
For example, if you expect to run a hot water faucet with a flow rate of 0.75 GPM and shower head with a flow rate of 2.5 GPM at the same time, the flow rate through the water heater needs to be around 3.25 GPM.
Below, you can find a table that shows average flow rates and temperatures for different fixtures in case you do not know the flow rates of your fixtures and need a reference.
|FIXTURE||AVERAGE FLOW RATE (GPM)||AVERAGE TEMPERATURE(OF)|
|Bath Tub||3.5 – 4.0||101|
|Shower||2.5 – 3.0||105|
|Kitchen Sink||1.5 – 2.0||110|
If you want to be more accurate about the flow rates, you can measure how long it takes for your fixtures to fill in a gallon. We highly recommend that you leave yourself a safety margin when deciding on the flow rates and the incoming water temperature.
The temperature increase:
Depending on the climate you live in, the incoming water temperature changes. For example, if you are living in a northern region of the country, your incoming water temperature will be lower but it will be higher in the southern regions. Let’s say that you have an incoming water temperature of 70 oF and you want to take a warm shower around 110 oF. Then, you will need your tankless water heater which can provide a temperature rise of 40 oF.
An average showerhead has a flow rate of 2.5 GPM and is around 105 oF. Assuming you live in an area with incoming water 70 oF and expect to run two showers simultaneously, you will need to be able to heat at least 5.0 gallons of water with a temperature increase of 35 oF. So, you will need a water heater that can provide at least 35 oF rising in temperature at 5.0 gallons per minute.
When you search for electric tankless water heaters, you will notice that the specifications give a maximum kW rating. This rating is the total heat the water heater can produce. However, not all the heat produced is transferred to the water. For example, some of the heat is lost to the pipes. The product specifications also list the efficiency of the unit, which you should definitely check before making a purchase.
Electric water heater efficiency is listed as only efficiency or thermal efficiency, and the average rating is usually somewhere between 0.95 (95%) and 0.99 (99%). To determine how much heat is transferred into the water, multiply the total kWs by the heater’s efficiency. For example, if an electric tankless water heater has 13000 watts of wattage and is 98% efficient, then you do the math as follows:
13.000 x 98% = 12.740 watts of heat get transferred into the water.
The range between 95% and 99% might seem small to you, only 4%. However, this 4% might add up to a remarkable sum depending on how much hot water you use in total in a month and create a load on your electric bill. That is why we strongly recommend that you do the math before making a decision.
Operating costs for different models and sizes of electric tankless water heaters may vary. However, you can easily estimate how much it will cost you by simple math. Let’s assume that you live in a household that consumes 60.000.000 BTU per year and also that electricity rate is $0.2 per kilowatt-hour in this region. Tankless electric heaters and heat pumps run on electricity, so first, the heating output must be converted to kWh:
60.000.000 BTU X 1 kWh / 3412.14 BTU = 17.584 kWh
Next, the yearly heating output is divided by the energy factor to calculate the yearly energy consumption:
17.584 kWh / 0.97 EF = 18.128 kWh
Finally, this value is multiplied by the unit price of energy, per kWh:
18.128 kWh x $0.2 = $3.626
In case you do not want to do all the calculations by yourself, here is a link for quick and easy calculation.
Apart from the operating costs, you should consider the maintenance costs. With most of the products on the market, you can do the maintenance yourself since it is quite a simple process that costs almost nothing. We have already described its details in the maintenance section. But if you are planning to hire a professional to do it, it may be a good idea to check how often your unit will need to be maintained and how much professional companies charge for it.
When it comes to warranty, there are a lot of differences in terms of coverage between different brands. However, companies mainly accept responsibilities for the following:
- Parts (around 5 years)
- Labor (around 3 years)
- Replacements (around 1 year)
Mostly, the part that comes with the longest warranty is the heating chamber. Many warranties do not apply unless the unit is installed by a licensed professional. Also, many companies wash their hands off of their warranty responsibilities if the unit’s periodic maintenance has not been properly done.
It is very important to check out the tankless water heater’s warranty. Since they don’t have tanks that deteriorate after years of storing water, the best tankless water heaters offer long-term reliability. Warranties on the most critical component, the heat exchanger, run from five to twelve years. This is quite a wide range and you will want to purchase the product with 12 years of warranty instead of 5, to be on the safe side. Also, warranty coverages on the other components and labor also differ from brand to brand as mentioned above. It is important to consider all of these to make a good choice.
Best Electric Tankless Water Heaters Comparison Chart
|PRODUCT||PRICE||DIMENSIONS||WEIGHT||ENERGY SAVING||MAX. WATER FLOW||TEMPERATURE|
|Stiebel Eltron Tempra Plus 24 Tankless Electric Water Heater||$$$$$||21 x 19 x 8.5"||20 pounds||15 to 20%||5.5 GPM||up to 140°F|
|EcoSmart ECO 27 Tankless Electric Water Heater||$$$$||3.6 x 17 x 17"||16.8 pounds||up to 50%||6 GPM||80°F to 140°F|
|Rheem RTEX-13 Tankless Electric Water Heater||$$$||4 x 9 x 13"||4 pounds||8 %||3.2 GPM||80°F to 140°F|
|Titan SCR2 N-120 Tankless Electric Water Heater||$$$||12 x 10 x 5"||2 pounds||40 %||4 GPM||above 65°F|
|Sio Green IR30 POU Tankless Electric Water Heater||$$||13.5 x 8.5 x 3"||6.4 pounds||up to 20 %||1 GPM||Variable|
|Stiebel Eltron DHC 3-1 Tankless Electric Water Heater||$$||18.9 x 7.9 x 14.2"||4.6 pounds||Up to 50 %||0.5 GPM||up to 40°F|
|Bosch Electric Tronic 3000 US12 Tankless Electric Water Heater||$$||12.2 x 3 x 6.5"||4.9 pounds||Up to 30 %||1.8 GPM||45°F to 75°F|
|Atmor AT-D18TP-AZ Thermopro Tankless Electric Water Heater||$$$||17.4 x 5.2 x 13.4"||17 pounds||Up to 50 %||3.7 GPM||90°F to 135°F|
|Ecosmart POU 3.5 Tankless Electric Water Heater||$||3 x 11 x 6"||4 pounds||60 %||0.5 GPM||37°F to 77°F|
|Marey ECO180 Tankless Electric Water Heater||$$$||11 x 3.5 x 16.1"||18 pounds||60 %||5 GPM||36°F to 80°F|
We have covered the best electric tankless water heaters on the market and hope that our well-researched analysis has helped you to narrow down your choices. We hope that you have identified your needs, understood what to look for when making a decision and feel confident to make a good choice that is best suited for your needs! In case you have decided that an electric tankless water heater will not satisfy your needs, make sure you check our reviews on gas tankless water heaters.