What Is The Downside Of A Tankless Water Heater? Complete Guide 2021

tankless hot water heater is one of the crucial home comfort investments. Therefore, you should choose the heater wisely because it is an optimal way to decrease your home energy expenditures and heat your water in an eco-friendly way. 

The on-demand or instant devices have numerous benefits over conventional ones and can be a splendid long-term investment. One of the most vital contemplations you will have to make is whether you should stick with the reliable traditional water heater or switch to a contemporary tankless one.  

What Is The Downside Of A Tankless Water Heater

What Is The Downside Of A Tankless Water Heater?

Like any other appliance, they also have downsides, and they are not an impeccable solution for every household. Tanked storage devices frequently utilize power to supply hot water, but the tankless units only spend energy when you activate the water faucet. 

Suppose you are thinking about replacing your existing machine. In that case, you must grab information about the pros and cons of on-demand heaters to determine if this technology is suitable for you. 

Because it is an appliance, you will be dependent on daily for more than 20 years. Have we designed this short post to help you understand the disadvantages of a tankless water heater? Also, we will inform you about their benefits. So, let’s get started.

Tankless Water Heater Pros And Cons 2021

Pros Of Tankless Water Heater

Save Energy And Money

Their most significant advantage is that they permit you to save a substantial amount of energy and money. The conventional units are insulated, but they are still not intended to prevent heat loss. 

It works continuously to heat the water in the boiler to provide you on-demand warm water. The constant heating increases the energy bills each month.

On the other hand, tankless appliances heat water only when you turn on the water tap and don’t store it in the tank. It warms up the water only when you need it, so they don’t experience heat loss. 

When you activate the water fixture in your house, cold water travels through the unit where the electric coils or gas-powered burner heats it.  


The tank-style appliance takes up a lot of space in your house. Thus, if you have limited space in your residence, a tankless water heater would benefit you. 

You can hang it onto the wall or under the sink because it features a compact design that permits you to save precious space in the apartment. 

Usually, folks fix the tank heaters in the basement, but you can install the tankless one in your attic, closet, or any other non-traditional location.  


The instant units are designed to last for at least 20 years because their components are readily available in the market. However, the tank heaters last for up to 7 to 8 years only.

A Minimal Hazard Of Explosion

Nowadays, it has become compulsory to satisfy the water heater installation code requirements. That’s why; both the tank and tankless heaters have a temperature and pressure relief valve that is liable for emancipating pressure and eliminating the odd of the explosion.

Lower Possibility Of Leaks And Water Damage

If you have hard water, minerals will accumulate within the container over time, leading to rust and corrosion and, ultimately, leaks. On the other hand, tankless machines don’t have a boiler, so there is no danger of leaks or flooding. 

It does not mean they are free of issues. They also develop problems over time that could lead to leaks, but the chances are meager. However, it is guaranteed that minor leaks won’t result in floods and cause any damages to your property. 

What Is The Downside Of A Tankless Water Heater?

Water Output

The traditional device operates on a grander level and supplies 40 to 60 gallons of hot water. So, multiple individuals can take advantage of that water while bathing, washing clothes or dishes, or making coffee at once. 

The disadvantage of tankless units is that they produce a limited amount of hot water. You can swiftly run out of the water if you take a shower and wash dishes simultaneously.

Higher Upfront Cost

The tankless models have a longer lifespan, but they have a higher upfront cost. Depending on the model and manufacturer, you will have to spend an extra $200 to $300 compared to standard units. 

However, you will be able to save a lot of cash on energy bills, so the additional amount may not affect your buying verdict.

Take A Long Time To Supply Hot Water

Another negative side of the tankless machines is that they take a long time to produce and supply warm water compared to tank ones. Keep in mind; the tankless ones don’t store the water in the tank. 

When you activate the fixture, the residual water in the pipes is cool or at room temperature. Once it is flushed out, warm water comes out, but it may take a minute or more, depending on the unit’s distance and faucet. 

The conventional heaters deposit the water in the tank, so you acquire pre-heated water, and it also comes out quickly.

Energy Demands

It does not matter whether you purchase an electric, gas, or propane-fired tankless device; you should remember that it requires an immense amount of power upon start-up. 

However, the tank-style unit stores the water in the boiler, so it needs lower amounts of energy to heat the stored water. Therefore, before picking any heater, check how much prompt energy is available through your gas or electricity connection.


Tankless water heating systems have various benefits over standard ones. They allow you to save energy, money and deliver instant and limitless warm water. 
Besides, they are smaller in size, never leak, and there is minimal risk of explosion. Best of all, they are made of durable and long-lasting materials, so they last for at least 15 to 20 years or more. 
However, the downside of a tankless water heater is that it has a higher upfront cost, uses an immense amount of energy, and doesn’t provide water at all in case of a power outage.

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