Before choosing the right gas tankless water heater for your house you need to consider some basic features of these on-demand heating devices. Luckily, there is a wide choice in terms of appearance. Besides numerous manufacturers offer models meeting various needs of the customers. So, before buying the item, it would be nice to keep in mind they differ in terms of the burner type, the power, the firing type, the gas pressure in the system, combustion pressure venting, and some other features available. But if you’re eager to skip this part and proceed to choose the model right now, check out this best gas tankless water heaters review.

The burner type

A gas tankless water heater can have either open or closed burner. When the burner is an open type one, the fire burns together with air drawn inside from the room. The air intake is at the bottom of the device. The fumes are vented out through a separate flue that should be installed in an apartment.

Closed type burner water heaters use oxygen from outside the house. Coaxial flue is installed with the heater itself. As a result, the fumes are vented out with the help of an in-built fan. Such heaters are usually expensive and have quite a complex construction.

Pay your attention to the fact that for proper fan operation in closed type burner heaters you need to use electricity. In case of power cut you will have no hot water running.

Water heater power

The next factor you need to consider while choosing the best gas tankless water heater is its power. This factor affects the overall performance quality. It shows the quantity of water, which the heater can warm up for a certain period of time.

There are three types of devices:

  • Low power – 17-17 kW;
  • Medium power – 22-24 kW;
  • High power – 28-31 kW.

It is wise to pick the right water heater, when you know exactly what purpose the device will be used for. A more powerful gas heater will be great, when you have several water supply points and you need hot water for more than just washing dishes. While less powerful models are typically used for heating water in a kitchen sink or shower.

Attention! While choosing the water heater with a burner, pay your attention to the fact that the performance is given for water heated up to 25 degrees. If you need to increase the heating temperature for low head, the performance will differ from the one mentioned in the device certificate.

Firing type

There are three firing types available in the market: electronic, manual, and piezo firing. It depends on the way the heater is turned on. No more matches and wicks! Today you can activate the burner with the help of buttons or it can even turn on automatically. Now let’s talk about each of the ways.

  1. Battery After you turn the tap on, the burner will be automatically activated. It is powered by batteries, the life of which is usually 3-4 months.
  2. Firing by means of hydro turbine. This kind of igniter is used in more expensive models. Here the burner is powered by an electro generator. This kind of device is a nice choice for cases, when the water pressure is over 0.35 – 0.5 bar.
  3. Piezo firing. The wick is fired by means of a special button with a piezo element. As this button is located in a hard-to-reach place, you will likely have some difficulties in using it.

Using the heater

Gas tankless water heater should be both functional and handy in use. It would be nice if the user could control gas feeding level and water head. In this case the burner will work even when the water pressure is low.

LED display makes it possible to see the following basic parameters of the device:

  • Output water temperature;
  • Flame control;
  • Error codes when the device is out of order, and some other features.

The burner operational safety

Even if we live in the era of technological progress, you need to consider this factor when buying a gas tankless water heater. So how to choose the item, which is safe in use? There are some requirements, that should be met by the manufacturers:

  • In case of gas or water supply shortage the burner must automatically turn off;
  • Gas leakage should not occur, when gas supply is resumed;
  • In case of poor draught, the device is automatically turned off.

To make sure the device meets the requirements listed above, manufacturers offer the following sensors in their items:

  1. Ionization sensor. When the fire goes out, the system turns the gas supply off.
  2. Firing sensor. This one performs the same function in case the ionization sensor doesn’t work.
  3. Emergency blow-off valve is used for controlling the water head in the pipes.
  4. Flow sensor. This sensor automatically turns the device off, when the tap is closed. And vice versa.
  5. Draught sensor. This one prevents people from carbon oxide poisoning, when there is no draught.
  6. Low pressure sensor. Thanks to this security system, the burner will not turn on in case of low water pressure.
  7. Overheating sensor. The main function of this sensor is to control the water temperature. When the temperature goes up, the device turns off. This additional security function prevents pipe breakage.

When buying the gas tankless water heater, make sure the item is equipped with those sensors. When at least one of them is absent, unfortunately, the device can’t be considered safe.