How Does A Tankless Water Heater Work?

Tank-style water heaters are extremely popular, and most American homes rely on these types of heaters.

Unfortunately, they are large and take up a considerable amount of space. It makes you wish there were a smaller, more compact solution, doesn’t it?

Luckily these days, tankless water heaters are gaining traction and popularity. They do the same job most traditional tank water heaters do while being much more compact and energy-efficient.

So how does a tankless water heater work exactly?

This article will explain everything you need to know about how tankless water heaters work and why they’re better than their tank-style counterparts. So let’s jump right into it!

How Does A Tankless Water Heater Work Exactly?

As their name implies, tankless heaters do not utilize tanks to store water. They directly heat water on-demand.

Water doesn’t have to stay in storage tanks while losing heat until there’s a demand. 

When you turn on the tap for hot water, the heater unit will draw cold water in and instantly heat the exact amount of water that is needed.

It means you never have to reheat the water. The powerful heating element ensures that the heating process is instantaneous.

The tankless water heater continues to heat the water until you decide to close the tap.

It means that tankless water heaters don’t have to run 24/7 to maintain a tank full of hot water. This translates into tankless heaters being much more energy-efficient and have much longer lifespans than traditional tank water heaters.

This design concept does have its drawbacks, though; this on-demand heating limits the output flow rate of tankless water heaters.

When the hot water demand is too high, such as multiple showers running simultaneously, the tankless water heater cannot keep up.

Tankless Vs. Tank Style Water Heaters

Just like any other appliance, tankless water heaters have different pros and cons. 


Some of the pros include:

Compact Size: They are pretty snug because tankless heaters don’t need a bulky tank to store water in, meaning that they don’t have to take up a significant amount of space in houses. They can even be wall-mounted.

Energy Efficient: Due to their on-demand heating, tankless water heaters are up to 30% more energy-efficient than tank water heaters, resulting in lower monthly energy bill costs.

Longer Lifespan: Tankless water heaters, since they don’t have to work 24/7, also have considerably large lifespans. They last more than 20 years than a storage water heater that lasts somewhere between 9 to 14 years. So, that’s almost twice as long!

Safer: Since these types of water heaters don’t require storage tanks, they have a more negligible risk of having major flood leaks. You also don’t have to worry about sediment and mineral build-up from hard water that can cause corrosion.

More Convenient For Remote Appliances: They are an excellent choice if you want an independent hot water supply to specific appliances such as dishes or washing machines. They can also be installed in tiny bathrooms and even come as solar-powered tankless water heaters.


All this doesn’t mean tankless water heaters don’t have their shortcomings. Some of the drawbacks of tankless heaters include:

High Initial Cost: The initial cost of buying tankless water heaters is significantly higher than storage water heaters. Additionally, tankless heaters have higher installation and maintenance charges generally. In the end, though, the longer lifespan and decreased monthly energy usage pay back the original sum.

Lower Output Flow Rates: Due to their design, tankless water heaters struggle to consistently deliver hot water when multiple outlets are used. This outcome is mainly due to their lower flow rates compared to tank water heaters. All this makes it crucial to always get a tankless water heater with a decent flow rate. One thing to note is that gas-powered tankless heaters have higher flow rates than their electric counterparts.

How To Install A Tankless Water Heater?

Correct installation and proper maintenance of your tankless water heater increase energy efficiency and the lifespan of your heater.

However, installing a heater is no simple task. It involves knowledge of plumbing, electric wiring, gas connections, building code requirements, etc.

All in all, it’s not something an ordinary layman with no prior experience can do. When spending so much on tankless water heaters, it’s best never to go cheap and try to install it yourself.

If you are searching for a professional firm to replace or install a new tankless heater, One Shot Water Heaters offers reliable and budget-friendly water heaters installation.

Their team is full of experts who are skilled in the installation of all kinds of water heaters. Book your installation today!

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