Pros and Cons of a Tankless Water Heater


A tankless water heater, as the name suggests, is a water heater that does not store water in a tank. Instead, cold water flows directly into the water heater and the device uses either electricity or gas to heat the water. These are compact and efficient instruments that provide instant hot water.

However, I must declare that there are a few pros and cons that you may want to consider about a water heater without a storage tank. In the following sections, I will shed some light on some of these factors.


The following are some of the pros that I find tankless water heaters offer. If you do decide that the pros outweigh the cons, then this guide to some of the best tankless water heaters may be useful.

Instant Hot Water

The biggest advantage of a tankless water heater is that you can get instant hot water almost in a few minutes. You do not need to wait for any storage tank to fill up and then supply water to the heater for it to finally start heating the water up.

A tankless water heater works instantaneously. Cold water will simply flow into the heater and the gas or electricity (depending on the type of water heater you are using) will provide instant hot water.

Space Saving

Another big pro and one of my personal favorite things about a tankless water heater is that it saves a lot of space. Especially, if you want to use this water heater in a cramped bathroom, you will be saving a lot of space as it does not require a storage tank. By itself, the water heater is compact and will take up neither a lot of volume nor surface area. This space-saving quality also makes it relatively easy to install.

Energy Efficient

Tankless water heaters also tend to be more energy-efficient than traditional water heaters as you are not waiting for the tank to fill up and then the water to gradually heat.

Since the supply of water is instantaneous, the heater also works faster. It also does not need to keep running to keep the water hot, making it a more energy-efficient device.

To put it technically, tankless water heaters are able to eliminate the process of “standby loss”, which standard water heaters are a culprit of. They do not need to reheat water repeatedly. This also means that your monthly bills will reduce considerably when compared to traditional water heaters.

Perfect for Apartments and Smaller Homes

If you are a single person living in an apartment or a student living by yourself, a tankless water heater is the perfect fixture to install in your home. It provides hot water instantly and is ideal for use in apartments as it barely takes up any space and can meet the hot water requirements of a smaller household. Even if there are multiple people in the house, if you time their shower right, you can get instant hot water at any time of the day.


Having covered the pros (many of which are very compelling), the following are some of the cons of tankless water heaters. If tankless water heaters do not work for you, there are other energy-efficient options such as solar heating technology.

High Initial Cost

The biggest drawback for tankless water heaters, for most people, would be their price. While these water heaters come with less baggage, they also tend to last longer than standard water heaters, which can drive their price up.

The initial cost of purchasing the tankless water heater can be considerably higher than simply buying one with a storage tank. It is up to you to see whether the monthly cost benefits weigh out the high initial cost.

Limited Supply of Hot Water

Since there is no storage tank, the hot water supply will not be endless. Sure, this is not to say that water heaters with a storage tank have the ability to provide endless hot water. But you will certainly get hot water for much longer if there is stored water available for the device to heat.

So, if you are looking to take a quick shower, a tankless water heater is great. However, if you are into taking long hot showers, then I would reconsider opting for a tankless water heater.

Inconsistent Temperature

If there are several taps connected to a single water heater (as will frequently be the case in a household with two bathrooms), there is a great chance that the hot water’s temperature will not be consistent.

Often, you may find that if the faucet in both the bathrooms is on or if two people want to take showers simultaneously, the water temperature in one of the showers will not be adequately hot.

Additional Maintenance and Equipment

Tankless water heaters may require some additional equipment, such as water softeners. Though this may not be required in all water heaters, depending on the area you are in and the quality of water in your area.

But, limescale buildup inside the water heater from hard water can cause it to overheat and malfunction. A water softener can resolve this problem, but will cost extra money and will also take up extra space. The tankless water heater also boasts an additional lifespan, but that is not without regular maintenance and fixing. It will not necessarily be a smooth ride.

Final Thoughts

From the detailed pros and cons I have provided above, hopefully, you are presented with a clearer picture of whether tankless water heaters are worth it or not. I do think if you live in a small apartment or do not have extremely high hot water needs, a tankless water heater does the job perfectly.

However, if there are more members in your household and they all simultaneously require instant hot water, things may become slightly more difficult. Either way, there are some troubling cons and incredible pros for you to consider.

Leave a Comment