Tankless Vs Tank Water Heaters

Water heaters alone take about a quarter of the annual cost spent on energy in an average home. Equipping your home with a new water heater or replacing an old one is, therefore, an important decision taking note of the cost, durability, and efficiency of your preferred water heater. In response, manufacturers have stormed into the market, offering a vast range of water heaters; aimed at minimizing the cost and maximizing efficiency.

Given the busy landscape of the market, many homeowners have a hard time choosing between traditional tank water heaters and innovative tankless water heaters. In this context, we’ll weigh between the two water heaters to help you make the right decision before settling for buying any water heater.

Tankless Water Heaters

Tankless water heaters use burners to heat water that flows through heat exchangers. Cold water flows into the tankless unit. Seconds later, it flows out fully reheated as per the temperature desired by the user. These types of water heaters only heat water as you need it, hence the name ‘on-demand.

Heating water only on demand because they save more energy than tank water heaters, whereby water requires re-heating due to the thermal loss associated with storing the heated water in a tank. On-demand water heaters use either electricity or gas; however, electric models might turn out to be expensive as they require an upgrade of the home’s existing electrical capacity.

Gas-powered tankless water heaters are cheaper since gas prices are lower compared to electricity prices. For homeowners drawing water simultaneously, it is advised they fix a tankless unit at the point of demand. Simply because tankless heaters cannot provide hot water for more than one use at a time. Amazingly, the tankless water heaters are smaller in size. You can fix them almost anywhere in the house.

See also – How Does A Tankless Water Heater Work?

Advantages of Tankless Water Heaters

Saves Energy

By saving energy in a household, you end up saving money too with a low energy cost without limiting your daily usage of any home appliances. The tankless water heater uses less energy simply because there is no tank of heated water that has to be continuously kept hot. This lets you cut down on the energy cost whether you use a gas or electric powered tankless unit. Tank water heaters experience standby energy losses as the hot, tanked water may get cold. Consequently, it translates to escalating energy bills leaving your pockets with a big dent. A number of homeowners have confessed to saving up to $90 annually, thanks to the tankless water heaters.


Tankless water heaters have a long life expectancy of about 20 years. It is a guaranteed longer life of service without having to replace your water heater if well maintained. A typical tank water heater will only last for about 10 years. Tankless water heaters allow you to save a hefty price on a replacement, especially if you are planning to stick in your current home for a while.

Smaller Size

Saving space is one of the big advantages of tankless water heaters. These types of heaters are compact thus do not take up huge chunks of floor space thanks to their small size and can even be mounted on the wall or any other convenient space in the house. A typical tank water heater with a capacity of about 60 gallons of water is not only bulky but also tall and wide, meaning it requires a big surface area to be fitted in. The tankless water heater units generally free up space in your house for other things as opposed to traditional tank water heaters.

Cost Saving

Tankless water heaters have a low maintenance cost since they do not experience the rusting and sediment build-up, which is common in storage tank water heaters due to water just sitting up in the tank. The hard water scale that forms in tank water heaters makes the tank rust, raising the need to be replaced this problem is not common in tankless water heaters. As earlier mentioned, tankless water heaters use less energy as they only heat the water on demand. These contribute to the low cost of running a tankless water heater, thus saving the consumers money.

Unlimited Supply of Hot Water

Another advantage of tankless hot water heaters is that they provide hot water on demand without running out. So no matter how large your family is, a hot shower is guaranteed to everyone even when they wake up late. The case is different when a large family depends on a traditional tank water heater; the hot water may run out at some point, meaning some will have to miss taking a shower until more water can be heated.

Related article – Advantages of a Tankless Water Heater

Disadvantages of Tankless Water Heaters

High initial cost

It is more expensive to purchase a tankless water heater compared to a traditional tank water heater. Despite the high cost, about $1000, this system will pay in the long run. You still get a good value off your money considering the less energy a tankless heater needs for its running.

High installation cost

Tankless water heaters running on gas require the installation of proper vents and new gas pipes to cater to their gas supply needs. Moreover, even the electric-powered tankless water heaters require an upgrade of the existing electrical capacity so as to run perfectly. All these are additional costs on the already high initial cost of a tankless unit heater.

High BTU requirement

BTU is a unit used to quantify the amount of energy, in this case, gas or electricity, used in the heating and cooling of water in heaters. A conventional water gas water heater may use about 50000 BTU of gas or propane. A tankless water heater unit requires as much as 150000 BTU. Such a level of BTU is high and almost not possible since most homes have a low-pressure gas supply and are limited to a low BTU, spread among all the home appliances.

However, you can consult a plumber to determine whether a gas tankless water heater is the best option for you. Switching to an electrical gas tankless heater might also be challenging since you need to upgrade your electrical system. Electricity prices are over the years have proven to be higher than those of natural gas in many areas. You will need to consider this as well.

Tank Water Heaters

Storage tank water heaters are common in many households. These types of tank heaters pre-heats and store about 40 to 50 gallons of water in a heavy inner steel tank. Typically, conventional tank water heaters use either gas or electricity as fuel. The heating element in electric model tank heaters, or the burner in gas-fueled heaters, is controlled by a thermostat.

In case the water reserved inside the tank falls below the desired temperature, the burner fires, and the water is re-heated. The hot water valve opens, and water is drawn from the tank through a pipe emerging from the top. The hot water is replaced with cold water at the bottom of the tank flowing through the dip tube. If the tank used is too large, a lot of energy goes to waste, maintaining the temperature of the stored water. However, if the tank is too small, the hot water will not be enough for a household. It is necessary to use properly sized tanks.

Advantages of tank water heaters

Low initial cost

Storage water tanks are cheaper to purchase and install as compared to tankless water heaters. Buying and installing a tank water heater will cost around $600 to $800, while a tankless water heater will cost you about $5400 to do the same.

Simple and easy to operate

Tank water heaters are simple in the way they operate, and this makes them easier to repair and maintain. As compared to tankless water heaters, which are more complex, making it an uphill task to repair them leave alone purchasing one.

Disadvantages of tank water heaters

Wastes energy

Conventional tanks are always on. This is because they have to keep water in the tank hot whether the water is needed or not. This can bring about huge spending on a household energy cost. The extra energy needed to re-heat the water causes a significant difference between the two types of heaters.

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Big and bulky

Most tank water heaters have huge and heavy tanks for storing water. These tanks end up taking up a large space in any room, either mechanical or laundry.

Can run out of hot water

Depending on the size of the family and the capacity of water needed, storage tank heaters may fail to meet the demands. No one wants to take a cold shower. This problem can be fixed by replacing a smaller tank with a larger tank. However, this will increase the energy cost.

Which one is the best?

In large families where there is a constant demand for hot water, tankless hot waters are the most ideal in such a family. There will be enough hot water for everyone without having to worry about running out of water. Tankless water heaters save energy which in turn saves you money they have proven to be efficient in their operation too.

In spite of their high initial cost, you can save money in the long run by switching to tankless water heaters. Besides, you are not only saving money but also freeing up more space in your house that can be used for other purposes and it’s easy to clean.

Not forgetting that tankless water heaters are more durable than tank water heaters, the benefits of switching to tankless heaters outweigh the advantages of sticking with tank water heaters. But, if your budget is tight and wants a quick replacement, a tank water heater is the perfect choice for you.

Final Words

Choose the best water heater that suits your daily water usage and budget. Each homeowner should also consider the energy factor and operating efficiency of any water heater before settling for one. Consult your local plumber and weigh your options.