Electric Hot Water Heaters
Buying Guide (with pros and cons)

Electric water heater

A review of the electric hot water heaters for residential water heating including types, popular brands and models, advantages, disadvantages, what to look for, main parts, and tips on selecting the correct size.

Selecting electric hot water heaters and things to consider

Many manufacturers and dealers of HVAC equipment offer various electric water heaters throughout the US and Canada. They include different types, such as tankless or on-demand, and storage tanks, that come in many sizes, from as low as 2 gallons to over 80 gallons.

Small models used mostly for one fixture are available as the point-of-use and Lowboy models, while medium sizes include tankless and tabletop models. The largest models are cylinders with a capacity of over 100 gallons and are utilized in commercial and residential domestic water and radiant heating, including space.

Electric hot water heaters with storage tanks from 30 to 60 gallons are the most popular type, designed for the whole-house water heating and supplying hot water to more than one fixture.

Electric heaters are simple, easy to use, that rely only on electricity. They do not require venting and gas supply, making them more affordable than gas types and are cheaper to install.

Tank-type

Tank-type water heaters are the most common type in North America and are present in this market for decades. They use proven and reliable technology, so water is heated and stored inside an insulated tank until it is needed. Electric heaters are recommended in areas where natural gas is not available and to supplement solar water heating.

Best selling models and features to look for

• Rheem Marathon 50-gal
• Westinghouse 80-gal
• AO Smith PXNS50 50-gal 

Marathon tank

Electric hot water heaters with water storage tanks are a very popular type due to their proven technology and reliability. This type has a very simple design; a tank surrounded by foam insulation and one or two heating elements.

For the best electric models, look at those with a longer warranty, usually 12 years, that utilize Incoloy heating elements and protection against dry-firing. The powered anode or commercial grade type is recommended, including a special dip tube for self-cleaning and reduced sediment build-up.

One of the top-rated electric hot water heaters is Marathon 50-gal from Rheem. The Marathon series comes with great features such as the non-metallic tank - so no corrosion, leaking, and rusty water, also no need for the anode rod made to protect a metal tank. They come with a limited lifetime warranty.

Another model, Westinghouse 80-gal., is the best selling on amazon.com, and one of the features that stands out is the stainless steel tank that also provides a limited lifetime warranty.

Tankless

Electric tankless water heaters heat water on demand, supplying endless hot water to one or two fixtures mostly and in continuous flow.

Tankless models have a small size, nice look and are usually installed on the wall, saving you floor space for other use. They cost more than the tank-type but can reduce energy consumption by one-third.

If the tankless is your option, make sure that your home's electric panel is properly sized.

Find out more about the differences between tank and tankless type here.

Top-selling models and features to look for

• EcoSmart ECO 27
• Titan SCR2
• Stiebel Eltron Tempra 24

Ecosmart tankless

Electric hot water heaters with tankless technology are the favorite type of many homeowners, and here is why; tankless are small and compact; they provide hot water on demand and in endless supply, and with high efficiency of close to 99%. Installed mostly under the sink, electric tankless delivers water instantaneously to one or more fixtures.

For example, one of the best models,  Tempra Plus 24, from the reputable German manufacturer Stiebel Eltron, comes with advanced engineering and a smart microprocessor, so hot water is always delivered at a steady temperature even if the flow varies.

Moreover, looking at the online store amazon.com, EcoSmart ECO 27 is the best-selling model. It comes with advanced features such as self-modulating technology, 27 kW of power, and up to 6 gallons of hot water delivery (enough for homes with up to 5 fixtures), reliability, and a limited lifetime warranty.

Heat pumps

GE heat pump

Heat pumps, also known as hybrids, are the most efficient electric water heaters that are also Energy Star compliant.

Users can save substantially by taking advantage of the tax breaks and incentives offered by the government authorities and utility companies.

This 80-gal heat pump from GE is one of the models recommended by hundreds of homeowners and builders; it comes with the high 67-gallon first hour delivery and ultra energy efficiency of around 3 (three times more than the standard type, providing savings up to $490 in households with 3-4 family members.

Basics to consider

When selecting a new electric water heater, consider the following:

• What are the hot water needs of your family (household)? Do you have a large family with teenagers and small kids?
• Make sure the recovery rate and first-hour rating can meet all your needs for hot water. Useful specs can be found on the energy guide label, together with the estimated yearly energy cost.
• What is the storage tank volume? Popular sizes are 30, 40, 50, and 60 gallons, and the size you buy is often linked to the size of your household.
• What is energy efficiency? Look for the high-efficiency models, or models with lower standby heat loss, because they will save you more.
• What are the purchase and installation costs? More advanced electric water heaters, especially high-efficiency models such as hybrids, are expensive but save you the most.

Advantages

• You can buy one of four different types; tank-type, tankless, heat pumps, and in conjunction with solar.
• Even with the low recovery rate, the advantage is high tank capacity.
• Easy to install. Find out how to install an electric water heater.
  
• It can be installed in many areas of a home.
• It can be installed close to the actual point of use.
• Various sizes and models.
• No venting is needed; there are no exhaust gases.
• The cost is significantly lower than on the gas heaters.
• Longer service life.
• Energy efficiency goes to 99% for standard type and over 2.5-3 on heat pumps.
• Electricity reaches more households than gas.
• Electric tankless water heaters are one-third of the size of gas heating systems.
• Very little maintenance needed, easy to clean.
  
• Much easier to diagnose the problem, troubleshoot, and repair. Find out how to troubleshoot an electric water heater.
  
• They are safe - safer than gas types.

Disadvantages

• Expensive to operate - electricity costs more than gas.
• Low recovery rate.
• Electric tankless water heaters are high amperage devices, and when hot water is used during peak times, its operating cost increases.
• Even with the lower cost for installation, you have to consider an adequate electrical supply, to support this high output hot water heating appliance.
• The biggest problem with electric hot water heaters is that they lose heat through the tank's surface, also known as standby heat loss.
• They fall into the category of water heaters with low recovery rates (the lowest actually), so it takes longer to heat the water.
• The solution to this problem is to cover them with a specially designed insulation blanket or "jacket."

Main parts

• The cylindrical storage tank holds the water. Typical sizes for residential electric hot water heaters are 40, 50, 60, and 80 gallons.
• To keep the rust out of the unit, the steel tank has a bonded glass liner.
• Insulation - helps to keep the heat inside the tank longer.
• Cold water inlet and a hot water outlet or pipes.
• Thermostats to control the water temperature inside the tank.
• Heating elements, usually two, upper and lower, are designed to heat the water.
• A drain valve that allows you to drain the tank.
• Temperature and pressure relief valve (TPR) - safety feature.
• Sacrificial anode rod - prevents corroding. Some models have a non-sacrificial powered anode.

How electric water heater works

The water heating process in tank-type electrical hot water heaters is very simple. There are usually two heating elements submerged inside the water (immersion-type), one in the upper part of the tank and one at the bottom, and two thermostats, one for each heater.

• Cold water enters the tank heater through the dip tube and fills it from the bottom up.
  
• The top thermostat pressed against the tank controls the upper heating element and turns it on when needed.
• Cold water is becoming warmer, and when it reaches the pre-set temperature, the power is switched from the upper to the lower heating element.
• Now, the bottom thermostat, which controls the lower heating element, turns the element on until the water temperature reaches the pre-set value.
• A safety device - a high-limit switch reacts if the water becomes too hot, cutting the power to heating elements.
• Once you open the hot water tap, hot water is drawn from the top of the water tank, and at the same time, the cold water enters the tank and lowers the temperature that triggers the thermostat. The water heating process starts all over again.
• If there is excessive pressure in that tank, which is usually a result of the high water temperature, another safety device - a pressure relief valve, opens and releases some hot water, reducing the pressure.

The thermostat is a switch, and it can sense a change in water temperature. The switch closes to allow current flow, and it opens when the temperature of hot water reaches its pre-set limit.

The current passes through electrical-resistance heating elements, power is delivered, and it heats the water to the correct pre-set temperature.

The heating elements continue to carry current until the thermostats are satisfied. These heating elements are very efficient, providing about 99% of the available heat to the surrounding water.

On some tanks, the thermostat has a mark showing a maximum temperature and where to set the temperature that provides energy savings and scald protection.

Money-saving tips:

To reduce the heat loss through the bottom of the electric water tank heater, place the tank over a thick layer of firm thermal insulation.

By reducing the temperature setting by 10 degrees F, you can save between 2-5% of your electricity costs.

Also, insulate the water pipes with foam sleeves.

Conclusion

So the question is, should you heat your water with gas, electricity, or any other fuel source.

As we know, natural gas and electricity are the most common fuel sources in North America and the most affordable.

The advantage of electricity is its availability in almost every home, and that getting the natural gas line requires a substantial investment, while the propane gas cost more.

If you would like to have a reliable water heater that won't break often, does not pollute, doesn't require high initial investments, is cheaper to install, and requires little maintenance, buy an electric.

And if you would like to save even more, while the cost is not an issue, buy one of the hybrids/heat pumps that are Energy Star compliant.

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