How to Buy the Best Water Tank Heater and Buying Tips

How to buy the best water tank heater for your home? Explore advantages, disadvantages and find the most popular sizes and manufacturers of the hot water tanks. Compare tank-type vs. tankless.

Tank water heaters are also known as storage tank type or cylinders. Gas water heaters with storage tanks are the most popular type for water heating in North America where a 50-gallon capacity is a commonly used size.

With the available capacities ranging from 20 gallons to over 100 gallons, water heater tanks are designed as whole-house systems so they can supply hot water to more than one fixture at a time. There are also water heaters with smaller storage tanks, but those are recommended for point-of-use applications. Water storage tank heaters are recommended for homes with constant demands.


  1. Top sellers
  2. Manufacturers and top models
  3. Types
  4. How it works
  5. Selecting tips
  6. Buying guidelines
  7. How much does it cost to buy and install a heater
  8. Tank vs. tankless

Popular models

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Tank water heaters are using gas, electricity and solar energy for heating. As opposed to tankless heaters, the storage-tank type is a simple and economical device where the tank occupies most of the unit. The storage tank is insulated so the heated water can stay hot longer. Every unit made of metal has the anode rod, thermostat, dip tube, TPR valve, and drain valve.

Gas-powered water tank heaters also have a gas valve, burner assembly, gas combustion chamber and the flue baffle (vent).

Almost all new gas water heaters are equipped with the FVIR system that is designed to protect from accidental fire caused by flammable vapors. From the gas burner, through the tank and water stored inside, there is a flue tube that moves the gases out, either naturally (atmospheric vent units) or forced (power vent units).

Most of the gas water heaters are using a pilot light for lighting the main burner, while others that are more advanced, use a hot surface or electronic ignition.

Electric water tank heaters are the simplest units that utilize upper and lower heating elements for heating the water.

Solar water tank heaters are storage tanks that store heated water (from solar panels) with an addition of the heating elements, for backup heating.

How does the water tank heater work

Gas water heaterGas water heater
Electric water heaterElectric water heater

The storage tank located inside the heater is where the cold water enters for heating and where hot water is stored for use. Incoming cold water is coming from home plumbing through the inlet tube or dip tube to the lower part of the tank.

Water is heated either by heating elements (electric type) or gas burner (gas type) and as it is becoming hot, it rises to the top from where it is going to, through the plumbing to the hot water tap (once it is open), or appliance, such as a dishwasher.

Every gallon of hot water that exits the water tank heater is then being replaced by cold water again through the dip tube. The thermostat, which measures the temperature of the water inside the tank, is what signals the heater to start heating by charging the heating element(s).

Selecting the right water heater

Choosing the right water tank heater results in sufficient amount of hot water for the whole household, convenience, comfort, and savings. This is what you should consider before buying:

  • How big is your family?
  • How many applications (shower, dishwasher...) will be using hot water?
  • The usage pattern of your family members: frequent short or high-flow and high volume draws.

Calculate the peak demand or the busiest one-hour usage period based on the numbers from below:

For the shower you need at least 20 gallons of hot water, for shaving - 2 gallons, hands and face washing - 4 gallons, food preparation - 5 gallons, automatic dishwasher – 14 gallons and so on. So, if you have calculated that you need 50 gallons of hot water, you would buy a 70-gallon water heater (70% is the available volume).

Buying tips

  • Buy the energy efficient water tank heater or Energy Star approved. To meet the Energy Star requirements, the Uniform Energy Factor (UEF) has to be 0.67 or higher. UEF is what indicates how efficiently the heat is transferred to the water. Condensing units have the highest efficiency which can be more than 0.9. High-efficiency water heaters are usually equipped with heat traps and have thicker insulation and R-value. For heaters with lower efficiency, it is recommended to use an insulation blanket.
  • Buy a heater with a large anode rod or with more than one because such units have an improved warranty and are protected from corrosion. Powered anodes are even better, as they are not sacrificial.
  • For a family of four to five, a 50-gallon tank size is often sufficient. Use the following instructions for sizing a water heater.
  • If it is needed, look for the high First Hour Delivery and recovery rate, and low standby heat loss.
  • Gas heaters are a good buy as they have higher First Hour Rating than the electrical ones. So, you might need a smaller unit for your water heating needs than the electric.
  • Look for the tank-type heater with a self-cleaning system as it automatically fights the sediment build-up problem; also green or low NOx burner, high recovery, high performance or high efficient models.

The First Hour Delivery and other info can be found on the Energy-Guide label.

How much does it cost to buy and install a water heater?

What is the average cost of a tank-type water? Depends on where are you buying from; hardware store, contractors, online shopping...

In Canada heaters can cost you between $800 and $1200, while installation can cost between $300 and $400.

In the US, expect to pay approximately $1300 or higher for advanced models, and that includes a water heater, supplies and labor. According to installation cost for the standard tank-type is from $150 to $600.

As explained by the installation cost varies according to several factors:

  • Size
  • Power source
  • Style
  • Quality
  • Warranty and other

An average cost to hire a plumber to repair a water heater, is between $100 and $160.

Tank water heater vs. tankless

Tank-type water heaterTank-type
Tankless water heaterTankless
  • The tank-type has lower upfront cost so as the installation.
  • Smaller burner and heating elements.
  • Cheaper venting system.
  • No electricity required.
  • The tank-type heater has to deal with the standby heat loss as the water is heated when not in use and as it is losing the energy through the outer surface.
  • A gas tank-type heater provides hot water even during power outages. No electricity is required.
  • They are free-standing, therefore, occupying valuable floor space. The dedicated room is needed for the gas type.

If you need more information, check out this article, where it explains tankless vs tank-type in details.


You cannot go wrong if you buy a tank-type water heater. They are affordable, utilize proven and safe technology, and can save significantly if you chose a condensing or high efficient model, such as Vertex from AO Smith or Polaris from American.

If you have to decide between electric and gas, go with the natural gas model. It is cheaper to use in the long run, and it heats water fast. Energy Star models are available from all manufacturers.