Water Tank Heaters
Buying Guide

Gas water heater

Explore gas and electric storage water tank heaters - the most popular type of home water heating products. This guide is a comprehensive buying guide where the homeowners can get everything they need for the proper tank selection, including; the best models, popular 50-gal models, selecting and sizing tips, also tips for removing and installing, cleaning, and draining, maintenance and troubleshooting.

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If you are looking for the 50-gal gas-powered hot water tank, check out our selection of the top models here, while if electric is your only option, see this review.

Water tank heaters, also called storage, stand-alone and conventional water heaters, are very popular in North America.

If you own a condo, you are probably renting one of 40- or 50-gallon tank-type units, as I do from the Reliance company (my Rheem power vent model was part of the deal when I purchased the condo), and for a monthly charge.

Alternatively, you can buy one for the price ranging from several hundred dollars for the economy gas or electric models up to a few thousand for the best models that use the most advanced features, such as condensing gas or electric heat pumps.

If you are not sure whether to rent or buy one, read the article to compare and see the pros and cons.

Buying guide

Tank-type water heaters are the most popular type, mainly because of the established market, extensive distributor and service network, reliable operation, and good up-front cost.

Before going into details, and just to have an idea of what other homeowners are searching for, here is the short list of the popular selling models found on amazon.com:

Type selection

Gas water heaters are probably the best option for homeowners who live in areas where natural gas is available.

Propane or LPG is also a good option but is more expensive and requires frequent gas delivery.

Gas models are, in general, more expensive than electric but cost less to run and offer more choices with greater flexibility.

The best ones are ultra-high efficient or condensing including Vertex from AO Smith and Polaris from American.

According to the Union Gas company (Canada), you can save between $300 and $400 a year (data from 2016) compared to electric, but it depends on the fuel rates and compared models.

Electric water heaters are the most affordable option, available to many homeowners, but cost more to operate. For those looking to get more in return for their investment, electric heat pumps are the way to go, as they can deliver more hot water faster and efficient than conventional types. Good choices are Rheem Professional and Voltex from AO Smith. 

Solar water heaters are probably the best choice in southern regions such as Florida due to longer periods of sunny days.

The main advantages are the green technology as they use free and renewable solar energy and are eligible for government rebates, stimulation, and support.

The alternatives to the above fuel types are oil-fired burners and wood heaters, but these are less popular.


Before buying a water heater, it is essential to determine how many gallons of hot water are needed for you and your family or what is the capacity of the water storage tank, measured in gallons.

The capacity of the water tank-type heaters ranges from 20 to 100 gallons, and the most popular sizes are 40, 50, 60, and 80-gallon tanks as they produce enough hot water for the family sizes of 4-6. These are known as the whole-house units that require some floor space and clearance around and above for the installation and service.

The best places for the installation are the utility room, laundry, basement, or garage. An attic is also used for the installation, but this location has some disadvantages that should be taken into account.

Note: Due to the higher recovery rate, you would choose a gas water heater with a lower capacity than an electric unit and for the same family size.

Small size tanks of only a few gallons, like the electrical heater Ariston from Bosch or SHC Mini-Tank from Stiebel Eltron, are mainly used for point-of-use applications and are installed near the faucet or shower.

How to select a water tank heater and what you should know

"When is the best time to replace a water heater?" - many homeowners will ask.

According to the experts, the average life expectancy of the water tank heaters is 13 years. For tankless is longer, it is over 20 years.

Most of today's water heaters have a warranty of 6 years, while the good-quality ones equipped with one or more commercial-grade anodes come with a warranty of12 years.

The warranty found on tankless models can reach 15 years.

The capacity, first-hour rate, recovery rate, and energy efficiency are the most important factors when selecting the best water tank heater for home use.

Other features might also be of your interest, and they include the advanced system such as the self-cleaning, diagnostic system and intelligent gas control valve. Also, LED display, hot surface ignition, flue damper, power or direct venting, number of anodes, material quality, etc.

Size. Choose the right tank size which will meet the demand at the peak time, but don't select an oversized model as the energy cost increases. Here is the sizing guide for more info. If you are not sure, ask a plumber or HVAC technician for the advice.

First Hour Rate. Hot water delivery capability or first-hour rate is a combination of the tank capacity and recovery rate, or how much hot water it can produce in one hour.

Recovery Rate. The recovery rate shows how much hot water a water heater can produce in a given period. When comparing two water heaters, one model has a faster recovery rate if it has more BTU or Watts than the other model.

Keep in mind that the greater the demand for hot water is, the higher the recovery rate you need.

Efficiency. High-efficiency water heaters are more expensive but pay off faster; also, they come with higher quality, efficient energy use, and better warranties. They are also environmentally friendly.

Such models have thicker insulation, more efficient heat exchangers, factory installed heat traps, improved gas burners, and venting.

The efficiency of gas, propane, and oil-fired water heaters is measured by a uniform energy factor (UEF). Higher - better.

Benefits of the conventional water heaters

  • Simple design
  • Less demanding
  • Cheaper than tankless water heaters
  • High efficient and Energy Star models available
  • Condensing models available
  • Capacity ranges from 2 gallons to over 100 gallons
  • Several sizes available; tall, short, lowboy
  • No minimum water flow required; they can be used for low and high demanding applications
  • If you have a gas-powered water heater, hot water is available even during the power outages
  • Smaller gas requirements
  • Easily adapted for use in solar water heating
  • Great for smaller families

How does a tank-type water heater work?

Conventional water tank heaters have a very simple design that allows easy floor installation, vertically positioned. The main part is the water storage tank, usually made of metal, where hot water is stored and further used for a shower, bath, dishwashing, or washing machine.

For better heat retention, a metal tank is covered with foam insulation with a thickness of 1 to 3 inches and a different R-value (higher better).

Cold water enters at the bottom of the storage tank through the dip tube (cold water inlet), and after it is heated by the gas burner or electric heating elements, hot water rises to the upper section of the tank. From there, it is transferred through the hot water outlet and to the open tap. At the same time, the hot water gets replaced with the cold water.

This process repeats, but it depends on the water temperature. If it is lower than the set value on the thermostat, the water heater keeps running; and once it reaches the set value, the heating stops.

Some models are equipped with innovative technology such as sensors, flow valves, electronics, and electrodes, providing better performance, greater efficiency, and comfort.

The main components found in electric and gas water heaters are explained in this article.

Note: Even with the simple design, tank water heaters have to be installed, maintained and troubleshoot, so the recommendation is to contact the plumbing expert.


Here is the list of the popular brands/manufacturers of HVAC equipment, including water tank heaters, in North America:

  • American
  • AO Smith
  • Bradford White
  • GE or General Electric
  • John Wood
  • Kenmore
  • Marathon
  • Whirlpool
  • Reliance
  • Rheem
  • Ruud
  • Richmond
  • State

Tips to save money

High efficiency. If you have an old tank-type water heater, replace it with an energy-efficient heater, as the higher efficiency provides more savings in the long run. Look for condensing models, such as Vertex from AO Smith or Polaris.

Get the model that is solar-friendly.

Install an insulation blanket. How to check if your tank water heater is wasting energy? Put your hand on the outside surface of the tank, and if it feels warm, your unit needs better insulation. Once you install the insulation blanket or "jacket," the standby heat loss will decrease, and your savings increase, like energy-efficient units with thicker foam insulation. If you are considering buying a new unit, choose one with the higher insulation value (R-24 will be the best).

Insulate. There is a lot of heat and energy wasted when waiting for hot water to reach the tap. Insulate all the pipes, especially sections going through the unheated areas, and you will reduce the energy loss.

Lower the temperature. You can also save if you lower the temperature on the water heater thermostat by a few degrees.

If you reduce the temperature on the thermostat by one degree for eight hours, you will reduce the energy consumption by one percent.

The recommended temperature is between 120 and 140 degrees F, while the factory set temperature is between 120 and 125 F.


Water tank heaters are a good choice for small and mid-size households, where demand for hot water is not high, and for people who would like to stick to old and proven technology.

As opposed to tankless, storage tanks use the energy at a slow rate and store the heat for later use.

While most of the tanks are low efficient, there are still high-end models, whether electric or gas, that can come with an ultra-high efficiency of over 90%, innovative design, and significant savings. These are, as mentioned above, Polaris and AO Smith Vertex from the gas type or Rheem and AO Smith electric hybrids.

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