PROS and CONS of Tankless Water Heaters – Should You Buy Or Not

Pros and cons of tankless water heater

You will learn the PROS and CONS of Tankless Water Heaters, what are the downsides, and are tankless water heaters worth it?

PROS and CONS of Tankless Water Heaters

According to the US Department of Energy, tankless water heaters are highly energy efficient as compared to an average water heater. They are also referred to as instant or on-demand water heaters that have many advantages over traditional tank water heaters and investment in them can be worth it.

With so many advantages, tankless water heaters have some downsides too and they do not prove to be a perfect solution for every home. As it is the best option for energy and cost-saving but there are many other factors to prefer tankless water heater over some traditional tank water heater.

It has also many CONS that we are going to mention here so according to your unique situation you can make a well-informed decision.

So, here is the detailed list of PROS and CONS of tankless water heaters to decide whether they are worth it or not.

PROS of Tankless Water Heater

#1. Hot water on-demand

pros and cons of tankless water heater - hot water on demand

An unending stream of hot water comes out of the faucet instantly from a tankless water heater. Without the inconvenience of storage tanks. These can supply hot water on demand. There is plenty of hot water 24/7 without any delay and difficulty.

The flow rate of a tankless water heater decides the amount of hot water at a given time. With maximum flow rate, you will be able to run 5 showers at once that some storage tank heater won’t be able to keep up.

#2. Longer Lifespan

An average tank water heater lasts for almost 8-12 years maximum; however, a tankless water heater can last for more than 20 years. If you have a plan to live at a place forever then a tankless water heater is worth it.

#3. Lower Monthly Cost

The efficiency of a tankless water heater is unbeatable. It has been reported that these water heaters are 22% more efficient as compared to others. Homeowners can expect to save hundreds of dollars annually.

#4. Space Saver

pros and cons of tankless water heater -space saving

They do not require plenty of space because a tankless water heater can be mounted to the wall and takes very little space as compared to a traditional tank water heater.

Anyone who has spent his life with cylindrical tank heaters or heat pumps in the basement, garage, or kitchen would be astonished at the size of this sleek tankless water heater.

#5. Eliminates Standby Loss

The best part of a tankless water heater is that it eliminates standby loss. Traditional water heaters reheat water repeatedly by raising energy costs every time. Even if there is no one at home, the energy will be used up by a water heater to reheat water in the tank.

#6. Both Gas & Electric Tankless Water Heater is available in the market

Most of the tankless water heaters are powered by natural gas but electric tankless water heaters are also available on market. It depends on the infrastructure of a home’s electricity or gas availability, which of them will be perfect to install at your home.

Gas water heaters are extremely popular, we have made a list of top gas units available on the market.

#7. Offer Longer Warranties

If anything goes wrong with your tankless water heater, you don’t need to worry about repairing payments. Due to their long lifespan, tankless water heaters have longer warranties, and these warranties can run up to 20 years or more.

#8. Ideal for Smaller Families

Smaller homes with few family members have minimal requirements for hot water. These units are efficient to eliminate standby loss and there will be a sufficient amount of hot water to use for different purposes.

#9. Energy and Cost Saving


The major advantage of a tankless water heater is its ability to save money and energy for a long period. A tank heater will use maximum energy to raise the temperature of water present in the tank, while a tankless water heater provides water on demand without consuming much energy. Constant heating in-tank heater also causes an increase in the cost of your energy bills.

A tankless heater will heat water only when needed, so there will be no heat loss and all energy will be preserved. Energy consumption also depends on the amount of water usage.

According to Energy Star, switching from a traditional tank water heater to a tankless water heater will save $100 per year and $1500 or more throughout a lifetime for a family of four.

#10.  Less risk of leaks & damage


A great advantage of a tankless water heater is its lesser risk of leakage and damage that often occurs in the case of a tank water heater. Sediments and debris pile up in the tank water heater for a longer time leading to corrosion that destroys the internal structure of the tank completely.

Though tankless water heaters are not immune to issues and can also go through leaks or damage but heavy burns, exposure to toxic metals, or flooding the basement in case of leakage is a very rare phenomenon seen in them.

#11. No-Risk of Tank Explosion

Traditional tank water heaters are upgraded these days by having temperature and pressure release valves to eradicate the possibility of tank explosion. When heavy pressure builds up in the tank it can cause a massive explosion that is impossible in tankless water heaters. As there is no tank in them, there are zero risks of explosion.

#12. Environment Friendly

Tankless water heaters are efficient and use less fuel to heat water, while traditional tank water heaters consume a large amount of fuel and energy to keep water warm. So, with less use of fuel, they reduce environmental footprint by making tankless water heaters more environmentally friendly.

What is the downside of a tankless water heater??

The major downside of a tankless water heater is its cost of unit and installation that is quite higher than a traditional tank-style water heater. Including installation, it costs 3 times more than a tank water heater. Cost is not the only disadvantage, tankless water heaters have many other CONS that we have mentioned below:

Cons of Tankless Water Heater

#1. Inconsistent Water Temperature

It has been revealed by the consumer survey report that inconsistent temperature is one of the major reasons for buyer complaints. This problem usually occurs due to the improper functioning of the heater to provide enough heat to warm water in different outlets at once.

If multiple showers are running simultaneously, then your tankless water heater may not keep up with the hot water. To avoid this, a water tank with a maximum flow rate should be preferred.

#2. High Initial Cost


There is a high upfront cost of installation and unit of the tankless water heater. According to some advisors, the average cost for a 50-gallon tank water heater is almost $890 while the cost for a tankless water heater including installation is $3000.

They are mainly more expensive due to their high installation cost. Sometimes, there is a need to install special wiring to compensate for the massive load. Also, tankless water heaters are not so common as compared to tank-style water heaters, and ultimately they have higher labor costs.

#3. Takes Time to Deliver Hot Water

Another important downside of a tankless water heater is that it takes too long to generate and deliver warm water as compared to a traditional tank water heater. It doesn’t supply hot water to flow immediately when needed. The idle water in pipes will be cool and it will be better to remove that cold water first to get warm water.

Though tank water heaters also do not produce hot water at once they have already stored a supply of hot water to go and reach the outlet faster.

#4. Energy Requirements

Either it’s an electric tankless water heater or a gas tankless water heater; there is a need for a massive amount of energy to start the water heater. As a traditional tank water heater has reserves of energy so it uses lesser energy input to heat water.

There are maybe options to choose gas or electric water heater depending on the energy reservoir of a particular area. If there is plenty of gas available, the choice will be a gas tankless water heater, and if there is enough power supply, the electric tankless water heater will be preferred.

#5. Seasonal Issues

Location wise tankless water heaters can be installed anywhere but some challenges can be faced by people living in colder areas with extremely cold temperatures. When groundwater sinks in the winter months, a tankless water heater takes long enough to heat water instantly.

There will be a need for more hard work to be done by your tankless water heater that will add more wear and tear to the heating system. So definitely you will need to wait to get your desired hot water in such colder areas.

#6. Rerouting Gas Pipe Lines

There is a requirement of a non-traditional setup in a tankless water heater that makes the installation process more expensive. The overall cost of the project would be enhanced by contractors who insist to reroute the gas line or add new venting.

#7. Can be Replaced by Solar Water Heaters

The tankless water heater is not the only efficient option, solar water heating is also becoming popular these days. In a solar water heater, there will be no need to reroute gas lines or install advanced electrical fixtures. These types of heaters can be used under any circumstances dealing with installation costs in a much better way.

#8. Requires Additional Maintenance


Your tankless water heater will require some extra maintenance in case there is hard water and piles of calcium have to build up. So a softener will be needed to install in your water heater.

There will be additional federal tax credits for a tankless water heater because of their efficiency. Also for keeping the warranty valid, there will be the need for annual maintenance.

#9. No Hot Water during Power Outage

Some uncertain conditions could occur anytime at any place like a storm can knock out all power supply at your home and there will be no availability of hot water. Though gas tankless water heaters run through gas supply still there is a requirement for an electric control panel to operate the whole system.

So whatever the type of tankless water heater you have, if there is a power outage then there will be no hot water to meet your needs. While for tank water heater, stored water will be enough hot to use for several days.

Are tankless water heaters worth it?

After checking the pros and cons of tankless water heaters, we have concluded that there are some disadvantages of tankless water heaters, they have also several advantages over traditional tank water heaters. Highly efficient, energy-saving, effective, and environmentally friendly tankless water heaters are worth it.

Their lifespan is two times longer than a tank water heater.

About Fareed Nawaz

Aqua macho was started by Fareed, a renewable energy and clean environment geek who completed his degree in energy and environment in 2017. He has worked in EPA, water heater installation, and water treatment companies for 2 years before starting this website.

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