Tankless water heater

What is a tankless water heater?

A tankless water heater heats water directly without using water from the storage tank. When you open the hot water tap, cold water flows from the tap and a burner or electric element turns the cold water into hot water. Due to this, hot water can be supplied whenever it is on demand.

Tankless water heater

How Does a Tankless Water Heater Work?

As mentioned early, it heats water directly without the help of storage tank. Therefore, you don’t have to bother about the quantity of water present in the storage tank. However, a tankless water heater’s output limits the flow rate.

Normally, the tankless provide hot water at a rate of 2-5 gallons ( 7.6 – 15.2 liters ) per minute. Compared to electric ones, gas-fired ones produces higher flow rates. In large household, gas-fired model cannot supply enough water for multipurpose use. For example, taking a shower and washing clothes at a time can stretch a tankless to its limitation. To overcome this scenario, you can install two or more, connected in parallel for concurrent demand of hot water. You can also install separate tankless water heaters for appliances such as shower, cloth washer or dish washing machine that use more hot water in your home.

What are the Advantages and disadvantages of a tankless water heater?

For households that use 40 gallons or less of hot water daily, the tankless option  can be 24% – 34 % more energy efficient than conventional storage tank water heaters. They can be 8% – 14% more energy efficient for homes that use a lot of hot water around 86 gallons per day. If you install a tankless heater at each hot water outlet then you can gain even greater energy savings of 27% – 50%.

The starting cost of a tankless is greater than that of a conventional, but tankless water heater will be last longing and have less operating and energy cost, which counterbalance its higher pricing. Most tankless water heaters have an average life expectancy of more than 20 years. There are also some parts available in the market which can be replaced to increase its life expectancy. Whereas, storage water heaters last for 10 – 15 years.

The tankless can avoid the standby heat loss affiliated with storage water heaters. Although, gas-fired tankless water heaters tend to have higher flow rates than the electric  ones. the gas-fired can waste energy if they have a constant burning pilot light. When compared to a storage water heater, this can sometime offset the elimination of standby energy loser. In gas-fired, the pilot light heats the water in the tank due to which energy is not wasted.

The cost of operating a pilot light in a tankless differs from model to model. Before purchasing the heater, make sure  how much gas the pilot uses in the model you are considering. If you use a standing pilot light than always turn off when it’s not in use. This can save energy. Instead of a standing pilot light, you can also consider models that have an intermittent ignition device (IID). This device favors some gas kitchen and ovens.

Before purchasing ensure the following things:

  • Cost
  • Energy factor
  • Size
  • Type of the fuel used and it’s availability

What is the difference between a traditional and tankless water heater?

Traditional vs tankless

The traditional is designed in a way that it heats water which is stored in a storage tank. It preheats 40 or 50 gallons at a time. When someone uses the hot water for any purpose, now for example, to take a bath, the pre-heated water stored in the tank flows to the bathroom. The tank is filled again with new water from your water source. This new water is heated and stored, and this cycle continues.

The tankless heats water only when it is being used, instead of storing pre-heated water in a water tank. It uses a heat source (electric or gas) to warm up cool water whenever you demand.

The installation price of traditional water is half rate compared to tankless one. The complication of installation is also less in traditional heater. Tankless water heater are small and can be installed in many places. The life expectancy of a tankless is double time more than traditional ones. A tankless provides 2 to 3 gallons of hot water per minute. The traditional reheats water regardless of your water needs. This increases your utility bill.


Every type of water heater has it’s own pros and cons. It all depends upon your usage, financial ability and lifestyle situation. However, a traditional may make more sense if you have a limited income and need a quick replacement. A tankless uses a heat source (electric or gas) to warm up cool water on-demand whenever you need it rather than storing hot water in a tank.


Travis is The Head of Content Marketing at Uphomes.net. He loves to write about various home improvement products.

When he gets spare time, he loves to go for adventure activities such as surfing or skydiving.

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