How do tankless water heaters (Kenmore, Bosch, Whirlpool and GE) work? The Best explanation

A water heater with a tank stores hot water for a while. This can be great if you want hot water immediately. It can also save energy as the heater doesn’t have to turn on immediately. Tankless water heaters don’t have a tank and every time that you open up a faucet and want warm water, this system has to heat the water. This can require more energy but they won’t run out of hot water as water with a tank can.

It depends on your usage if you should pick a tankless or water heater with a tank. If you don’t use a lot of hot water, a tankless system can be profitable. Tankless systems are also smaller and don’t require as much space. They generally work with electricity or gas (natural gas or propane). At the moment it is a lot cheaper to work with gas but electrical heaters are becoming more popular as they get more advanced.


What is a water heater? Conventional vs combi systems

There are heaters that just provide hot water. Combi systems can also offer heating. This can be delivered via the floor or radiators. In a combi system, the small pipes provide hot water and the thicker pipes provide heating. Heating is a closed-loop system. The water in the heating system stays in it and can stay hot for a while. The advantage of this is that the water heater can prioritize the demand for hot water overheating if needed. 

Conventional systems are cheaper as they don’t need an advanced computer to switch between hot water and heating. These systems also don’t have to be that powerful. In some instances, a conventional system is installed if an addition is added to a house and the existing system wouldn’t be able to provide enough hot water.

Condensing vs non condensing

Recently these systems have become more energy efficient. They are reusing the heat so that they have to use less energy. This is called a condensing system. These systems require a higher upfront investment but you earn it back over time. 

Condensing systems need more sensors and new systems have advanced electronics to check if the system is functioning properly. They can provide an error code if things do go wrong. This makes them easier to fix. It also makes them very safe. Water heaters almost never explode as a lot of things need to go wrong at the same time. 

Electric vs natural gas vs propane

Electric systems are easier to install as you don’t need a gas line. You might have to upgrade your sockets though. Gas-based heaters need oxygen and have an exhaust. This makes them harder to install as you need an exhausting drain through your house.  

In essence, they both work in a similar manner as they both centrally heat the water. Gas heaters use a flame to warm up a chamber. The water turns around this in a pipe and takes up the heat. This is then used to warm up the water. Electric heaters use a similar system but they don’t use a flame. The combination of a burner and heat exchanger is also present. A sensor notices that water is needed and activates the heating element. Once the water has warmed up, it gets delivered to your faucet. This is the reason why your hot water might be tepid at first. The heating element takes some time to get hot. 

 It is important that the system gets checked to clean it and also to make sure that it is not leaking. Heaters often last more than a decade but fabrication or installation errors can make them break after a few years already. These devices can often shut down if something breaks, this avoids further damage.

Pros of waterless heaters:

These heaters take up less space. Heaters are often installed in a garage and people want to keep their storage space. Water heaters with a tank can take up quite a lot of space. It is possible to hang them on the wall but it still decreases the space that you have left.

They are quite durable and can last a decade or more. They require less maintenance than a water heater that has a tank.

Depending on how you use them, they can save you money. If you take a lot of long showers, this won’t be the case anymore. You can get endless hot water and this increases the comfort but people often forget that this can increase their water and electricity or gas bills. 

You can change the settings of the heater to make sure that it doesn’t have to work too hard. Lowering the water temperature can be a great idea but you have to be careful as this can lead to bacteria. 

Cons of tankless heaters

These heaters have a higher upfront cost. If you have a family that takes a lot of showers, it can be interesting to have a heater with a tank as the water is hot immediately and the tank can be filled when electricity is cheaper. 

They can also make more noise as they have to turn on every time that you open up the faucet to get hot water. This can lead to more wear and tear if you start and stop them often.

Maintenance of hot water heaters:

Hot water heaters need some maintenance. You have to clean the water inlet filter. This removes dust and particles from the water. Some people have a separate filter in front of the heater as well. 

If you have water with chalk (hard water), you might have to use vinegar to descale your tank. Chalk can clog the pipes and make your system work less efficiently. Some brands also offer special products to do this. It is often a gas and is easier to use as you don’t need a pump to circulate it.

The system also has to be cleaned. You will have to call a plumber to do this. Generally, this has to happen every 2 years. 

The condensation valve has to be opened from time to time as water can get in it. This is an easy process as you just need to turn a valve and get a bucket. 

Heat pump

More recently heat pumps are becoming more popular. They use geothermal (heat from under the ground) or heat from the air. These systems are more expensive but are getting more advanced. 

We also see a combination of solar and batteries that are becoming more popular. If this becomes more affordable, we can see more electrical heaters in the future. These systems still have to get a lot cheaper though so it can take several years or even a decade before they start to overtake gas heaters. 

To conclude, tankless water heaters have improved a lot over time. Sensors have made them a lot safer and more efficient. They use gas or electricity to function. Gas-based heaters are cheaper to run but more complex to install. In the coming years, we might see electrical water heaters become more popular as they can work in conjunction with solar panels and batteries. This can decrease the cost of running them. If you need a lot of hot water, you can consider a system with a tank as you get hot water without having to wait.