Complete Guide to the Best Electric Tankless Water Heater

Electric water heaters are undoubtedly the current favorite of costumers as far as indoor water heating is concerned. The reason is that such heaters are easier to install and maintain. Moreover, these require little space and can be fitted anywhere even if there is no ducting space available since these don’t require venting.

Nowadays the debate between choosing between an electric tank type and electric tankless water heater is raising confusion among consumers all over the world. Users need to know what basically is different between both types of heaters and how should they decide about any one type. In this article, we will be discussing all that you need to know about electric tank type and electric tankless heaters.

Electric Tankless Water Heater

Tankless Water Heaters

Demand type water heaters are also referred to as instantaneous water heaters or tankless water heaters. This is because these heat and supply hot water instantly when it is demanded and doesn’t store hot water. Such heaters never produce standby energy losses that usually are a necessary feature in tank type water heaters. This is why electric tankless water heaters are considered less energy consuming and ecofriendly option.

There are two kinds of tankless water heaters: point-of-use and whole-house heaters. The point-of-use heaters are usually compact, light weight, small and supply hot water for no more than two outlets such as a shower and a sink at most. This limitation is due to their small size as they can be fitted in a closet or under a cabinet. The benefit of point-of-use electric water heaters is that the lag time and water loss is very low. Whole-house heaters, as the name explains, are larger and suitable for large families/houses because these can provide hot water to multiple outlets simultaneously.


Tank Water Heaters

This type of water heater is also referred to as storage type heaters. Such heaters contain insulated tanks that can hold up to 120gallons of water with electric heating elements. At the top side, the tank is stratified with hot water and the cold water stays at the bottom side. This is how you draw off warm water and receive it consistently until hot water gets depleted.

Tank type water heaters lose heat constantly through the walls of the tank. The difference in temperatures throughout the insulated wall is huge even if the storage tank is insulated. Therefore, with greater insulation the amount of standby heat loss is significant.


How an Electric Tankless Water Heater Works

These heaters directly heat water without storing it into a storage tank. Tankless heaters start heating water as soon as a hot water tap is turned on. The cold water then travels into the unit via a pipe and an electric heating element warms up the cold water. There is a powerful heat exchanger that heats up the water according to the desired temperature. Heat exchanger is a device that distributes heat from one source to another one. Heat is transferred by electric coils to the water that eventually comes out from the water faucet. The exchanger gets activates by inward water flow therefore, when you turn on the hot water tap, it circulates via the activated exchanger and turns the cold water into hot.

Resultantly, a constant supply of hot water is delivered within minutes and users don’t have to wait for the storage tank to fill up with adequate amount of hot water. However, one cannot ignore the fact that as far as flow rate is concerned, tankless types offer limited water output.

Generally, hot water rate that a tankless water heater offers is no more than 5 gallons/15.2ltrs per minute. The flow rate of water is higher in gas powered tankless heaters in comparison to electric ones. If you want higher flow rate then you will have to install two or more such heaters.


How an Electric Tank Water Heater Works

To heat water, tank or storage type heater usually contains two heating elements at the upper and lower sides respectively. When these elements are immersed fully then they are able to distribute 90% to 99% of the heat. No matter if the hot water tap is turned on or off, within the tank the water will be getting heated and the preset temperature will be maintained.

The tank is continuously filled with cold water from the home plumbing via the dip tube that is submerged to the lowest and deepest corner of the tank. When the thermostat senses that the water temperature has dropped below the set value then one of the heating elements gets turned on. All the heating elements carry the thermostat that is usually mounted against the tank surface. When the user opens the tap, hot water rushes in from the top and fresh water gets inside the tank as the level drops. Heating elements are immediately activated to maintain the water temperature, which drops when used. This is how tank type heaters maintain constant hot water supply. When the set value is achieved then the heating elements are turned off until another “call to action.”


Comparative Analysis: Electric Tank vs Electric Tankless Water Heater

Safety wise both type of heaters are alright because these are already equipped with necessary safety elements like the high limit switch to prevent water from getting very hot or being boiled when reaching the required temperature or if the thermostat fails to work properly.

Buying cost of a demand or tankless type heater is higher than tank type but longevity wise tankless water heater is better. Typically, a tankless water heater lasts longer (up to 20 years) and its operating and energy costs are low as well. This means a tankless water heater offers greater return-on-investment and considerably covers its high initial cost. Comparatively, tank type water heaters may last up to 10 or maximum 15 years.

Tank type water heaters cannot prevent standby heat losses whereas there is no such issue in tankless heaters. Installation wise also, tank type heaters are a bit complicated to mount and install whereas tankless heaters are easier to install and operate. However, it is always a good idea to hire professional electrician to set-up and install your water heater whether tankless or storage type.

Summary Table of the Best Electric Tankless Water Heater Models Available

Heater Model

Picture

Links to Our Detailed Reviews

Our Rating

The EcoSmart ECO line comes has several power options.  The number in the product name indicates the number of KW at 240V.  We have individual reviews of the following models:


4.6

4.1

Like the EcoSmart series, Stiebel Eltron has a whole range of power options for the Tempra Plus line.  We have individual reviews of the following models:


4.9

As with the other big tankless brands, Rheem has a whole range of power levels.  The number after RTEX indicates the KW.  There's everytihng from the RTEX-04 up to the monster RTEX-36.  We have individual reviews of the following:


4.2

3.8