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Dangers of Tankless Water Heaters – Are these Safe?

Are tankless water heaters safe? Very difficult to answer in one word. Any appliance we use at home can be dangerous if we do not follow the safety instructions. In this article, we will try to explain the dangers of tankless water heaters. After that, we will be comparing the potential hazards and dangers between a tanked and tankless water heater. Finally, we will recommend some techniques to mitigate the possible chances of any unwanted incident.

Types of Water Heater

Before we start our in-depth explanation, let’s have a quick look at the types of water heaters available in the market.

Storage tank water heater:

These are conventional water heaters, suitable for a larger family. These heaters are not energy efficient.

Tankless water heater:

This kind of water heater does not have any tank. These machines heat up the line water instantly. Therefore, we often call these ‘on-demand’ water heaters.

Gas type water heater

A tankless water heater that uses natural gas or propane as fuel to generate heat.

Electric type water heater

These tankless water heaters use electricity as fuel to produce heat. The operating cost of this type is relatively higher due to the higher price of electricity. But in terms of safety, this type is the safest of all kinds of water heaters.

What are the Dangers of Tankless Water Heaters?

Carbon monoxide:

This gas is dangerous for human health. Combustion of natural gas generates carbon monoxide. Therefore, this gas can diffuse to your house if there is any leakage in the pipeline. Exposure to moderate to a higher level of carbon monoxide for a longer period of time may cause heart and respiratory diseases. Inhaling an excessive amount of gas can even lead to death.

Are All Tankless Water Heaters Dangerous?

First of all, you might already know that a tankless water heater can be run either by electricity or by natural gas. Any household equipment which is run by natural gas should be kept under regular maintenance because of the type of fuel we are using. In contrast, water heaters which are run by electricity are the same as other electric equipment at our house in terms of danger. Therefore, for an electricity-run tankless water heater, there is no danger regarding carbon monoxide.

Tankless vs storage tank water heater – which one is safer?

Apart from the danger of carbon monoxide, a tankless water heater is safer than a conventional storage-tank water heater. A storage tank water heater has an open flame heating system which may heat up the tank itself. On the other hand, in the case of a tankless gas water heater, there is no concern about overheating. Not only that, there is no risk of the tank exploding due to a sudden increase in inside pressure. Considering everything, the tankless gas water heater is a far safer option for water heating than a conventional tanked water heater.

How to mitigate the danger?

Proper installation

If you are currently using a conventional tanked water heater, you might not have gas and water line which are properly sized for a tankless water heater. Therefore, during the installation of a gas-run tankless water heater, you should resize the pipeline properly and take extra care of the vent exhaust system. You need to confirm a 100% leak-free gas line to prevent carbon monoxide diffusion. You can also keep a gas leakage detector to identify the presence of any unwanted gas.

Call a professional plumber

Tankless water heater plumbing procedure is important to mitigate risks. Choose your plumber carefully to install any gas-run home appliance. Gas in an invisible substance. Therefore, you will be unable to notice if any accidental leakage happens.


Keep your machine under regular preventive maintenance. If there is any repair issue, hasten to call the technician. Always keep in mind the danger of gas leakage. You may keep necessary plumbing tools at home to support any emergency situation.

Install outdoor:

You can mitigate your risk if you choose your tankless water heater location tactfully. There are a few large-capacity gas-fueled tankless water heaters in the market which are designed to install outdoor. If you do not want to compromise your safety, you may choose a suitable outdoor gas water heater.

Final Words

In short, tankless water heaters are SAFER than conventional storage-tank water heaters. The electric tankless water heater is the safest option of all. On the other hand, a gas run tankless water heater can be dangerous if there is any gas leakage. If we take proper care to install and maintain the machine, it will not create a danger to any degree. If we compare the potential risk of tank explosion of a conventional water heater, a tankless water heater imposes less danger to your family. Therefore, don’t panic. Maintain your heater regularly. If you are still afraid of potential danger, go for an outdoor heater. As you know the downside of a tankless water heater, now we hope that you can make a better decision during choosing an appropriate machine for you.

If you are interested, read our article on the best 110 volt tankless water heaters.