How long does a tankless water heater take to heat up (short answer)?

You know that feeling when waiting too long to heat the water in a standard water heater? It must be so exhausting. This is one of the reasons why you should have tankless water heaters because they fix these problems.

One of the main questions is how long do I have to wait for the water to warm up when using tankless water heaters?

Here is a quick answer: about 15-30 seconds. For a longer answer, please continue reading this text further where we consider all the process that is going on in one tankless water heater.

Tankless vs standard water heaters

Tankless water heaters are an innovation today, although they were created years ago.

One of the biggest advantages is that you no longer have to wait for hours for a certain amount of water to heat up just for you to take a 10-minute bath or use it for something else.

If someone in the family takes a long shower, the next in line must wait around 45 minutes to be able to take a bath.

All this wastes our time and irritates us because heating water with a standard water heater takes about 35-60 minutes while we can spend only 15 seconds and get it from a tankless water heater. Nowadays, we really do not have time to waste.

Why is a tankless water heater a desirable choice for you

Well, there is always the solution – tankless water heaters that bring you hot water whenever you need it and as much as you want it.

You do not have to worry about huge failures that could happen, because such devices are very reliable. It all comes down to the question of what your needs are.

If you need more hot water than usual, then the best choice for you is those that consume more electricity. Such water heaters are measured by the amount of electricity they consume, and gas as well.

Some people simply do not want to deal with explosive gases such as propane and natural gas, so they prefer electric tankless water heaters. But of course, before buying it is necessary to evaluate the situation very well, whether you have everything you need for the device to work functionally.

As time goes on, technology brings newer and newer innovations, so you can control this type of device with your smartphone as well. You need to connect your devices to Wi-Fi and turn it on when you need it. It is amazingly easy to work with and set up all the parameters such as temperature and time.

Electric and gas tankless water heater – overview

Now let us look at two types of tankless water heaters:

Electric tankless water heater

This type of tankless water heater is extremely convenient if you already have all the proper electrical installations in your home. The installation process is quite easy and takes up truly little space. It takes up less space compared to a standard water heater. They are very reliable and efficient.

How do they work?

These types of tankless water heaters must have a constant supply of cold water in order to be able to heat it.

How does it heat the water?

It depends on the internal structure: water enters the boiler, where the sensor detects it and turns on heaters (which run on electricity). The cold water passes through pipes that go in a spiral path to keep cold water long enough to heat.

After the water reaches a certain temperature a few seconds after (typically it is about 15-40 seconds), it comes out. Since this process releases energy and gases, they must be expelled by ventilation, depending on the device.

The truth is, you need a large amount of electricity to make the device work, but this type of device is economical and efficient.

On an annual basis with a family of four, you will probably need to spend about $900. For example, a 30kW electric tankless water heater will cost about $4 per hour. Depending on the voltage and amperage of electricity, the vast majority require 240V and 100A.

Gas tankless water heater

Gas tankless water heaters work differently (the difference is not that big) than electric tankless water heaters. They use gas (propane or natural gas) to heat cold water instead of electricity. Although they use gas to heat water, they still consume an exceedingly small amount of electricity which is not used in the process to heat the water, but only to start the process.

But we want to know how? In the internal structure of a gas tankless water heater, there are fans for air intake which are activated when the sensor detects that it is necessary to heat water.

The fans start to take air in, and the right mixture of gas and air will ignite the flames that heat the conductors through which the cold water passes. When the water is warm enough it comes out. This entire process is based on gas, of course.

How long does it take for a device like this to heat water?

Well, the answer is similar to electric tankless water heaters. It does not take more than 20-50 seconds to get warm/hot water.

This type of water heater is more expensive than an electric one, but they use gas which is cheaper than electricity. However, you will need to service gas tankless water heaters more regularly than electric ones.

If you decide to buy either of these two types of tankless water heaters, you need to maintain them regularly. This is the key to getting ‘instant’ hot water. If it takes longer than usual to heat water, then there is probably a problem that needs to be solved.

Where can you get tankless water heaters?

You can get these boilers in larger shopping centers, local distributors, plumbing companies… Some of the best brands are Rinnai and Takagi. They can also offer you the best solution for your situation and needs.

The normal temperature for these tankless water heaters is around 110 Fahrenheit. Well, the amount of electricity or gas are parameters that determine the time to get hot water.

Today, there are very modern and efficient tankless water heaters that do their job very quickly, and in 10-15 seconds hot water is ready. Fortunately, such devices are very reliable.