Water heaters can be a major investment into a home that the owners have to live with for a decade or more. This is why when it is time to upgrade your water heater, it is is vital to consider the cost, longevity, and efficiency of the new equipment. Engineering solutions has put together a comparison of tank vs instant water heaters so that when this decision comes around, you can make a more informed decision. Let’s go through the pros and cons of tank vs instant water heaters.

What Is An Instant Water Heater?

Tankless, instant, or on-demand water heaters are powerful burners that quickly heat water when it passes through a heat exchanger, and is then delivered to your sink or shower without being stored in a tank. These “tank-less” types of water heaters are typically powered by gas or electricity. They have also been found to be up to 22 percent more efficient than gas powered “tank” water heaters.

What Are Traditional “Tank” Water Heaters?

Storage tank water heaters are generally found in residential homes. The part that defines this type of heater is an insulated tank that holds roughly 30 to 50 gallons of water, that is ready to heat when it is needed. Pipes come from the top of tank to bring the hot water to where it is needed, like bathroom sinks, showers, kitchens, etc.

These storage tank water heaters are generally powered by either electricity or natural gas. The storage tank heaters that utilize natural gas use almost 50 per cent less energy than their electric counterparts. This results in less costs to operate, however they do cost more upfront than the electric models. The natural gas models are feature a pressure release and temperature valve that will open when either the pressure or temperature exceeds a certain limit.

Advantages of Tankless Water Heaters

Saves money in the long run.
On-demand water heaters (if powered by gas) will cost $100 less every year as long as they remain working. Electric instant water heaters will still save around $44 every year, this information comes from the US DOE.
Longer life cycles than the storage tank models.
Instant water heaters generally last 20 to 30 years, twice the life of a storage tank water heater. Take into consideration that in “hard water” areas, the life span of both types of water heaters may be reduced.
Is not as big as a storage tank water heater.
Instant water heaters are compact and can be installed in small spaces. They can also be hung on outside walls if your home is really lacking in space.
You’ll always have hot water.
You won’t have to wait any amount of time for hot water as it is constantly available. A lot of storage tank water heaters take a long time to heat water, due to the amount of water they must heat.

*By Behrat - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=14949590*

Disadvantages of Tankless Water Heaters

Much more expensive than storage tank models.
The installation of tankless water heaters can be expensive, if you are replace a storage tank model.
When replacing a storage tank model with a tankless, the plumber will have to spend much more time, incurring more costs and time as relocating the existing piping can be complicated.
The can sometimes be referred to as “output challenged”.
The hot water can sometimes “run out” if a lot of demand is being put on the instant water heater. If you have a lot of showers or hot water fixtures in a house, it can be a common occurrence that the water is cold from time to time.

Advantages of Storage Tank Water Heaters

Storage tank water heaters cost significantly less than instant water heaters.

Storage tank water heaters are cheaper to maintain than instant water heaters as they are much more simple.
Because of this simplicity, any repairs that do have to be made are much cheaper than on-demand models. Instant water heaters are more expensive and complex to replace and repair.

Disadvantages of Storage Tank Water Heaters

Utility bills are higher.
Storage tank hot water heaters will have to work more in the winter months if you live in a cold climate, as they have a certain pre-set water temperature to reach. This will again increase the utility bills of the house.
They are much bigger than instant water heaters.
If you cannot install them in the house, it can be challenging to find a place outside to install them, as the water can freeze if the temperature drops rapidly outside.
The hot water can run out, and it can take a while for it to heat back up.
If you have a large house, then a large storage tank hot water heater si needed, this will in turn greatly increase the costs to run the water heater.
They have roughly half the life span that instant hot water heaters have. You will have to replace them about twice as much.

So what do you think of tank vs instant water heaters? Do you have anything to add to this article, and are you considering installing either of these options in your house soon? Engineering Solutions would love to hear your thoughts in the comments below, and don't hesitate to contact us for your next engineering project!