Tankless water heaters, also known as demand-type or instantaneous water heaters, provide hot water only as it is needed. They don’t produce the standby energy losses associated with storage water heaters, which can save you money.

These are becoming more and more popular in our homes. Traditional or the typical storage-tank water heaters create energy losses that will increase your cost via loss of efficiency. The major benefits of tankless water heating units are the constant flow of warm water (as in comparison to a limited flow of continually heated warm water from traditional tank water heaters), and possible energy savings in general. The main drawback of these systems is their high initial prices, installation, and equipment costs are high.

We only warm our houses when we need in the same method that a tankless water heater is utilized just when the need for hot water and this is the main advantage of a tankless water heater.​

How Do Tankless Water Heaters Work?

Tankless water heaters heat water directly without the use of a storage tank. When a hot water tap is turned on, cold water travels through a pipe into the unit. Either a gas burner or an electric element heats the water. As a result, tankless water heaters deliver a constant supply of hot water. You don’t need to wait for a storage tank to fill up with enough hot water. However, a tankless water heater’s output limits the flow rate.

Typically, tankless water heaters provide hot water at a rate of 2–5 gallons (7.6–15.2 liters) per minute. Gas-fired tankless water heaters produce higher flow rates than electric ones. Sometimes, however, even the largest, gas-fired model cannot supply enough hot water for simultaneous, multiple uses in large households. For example, taking a shower and running the dishwasher at the same time can stretch a tankless water heater to its limit. To overcome this problem, you can install two or more tankless water heaters, connected in parallel for simultaneous demands of hot water. You can also install separate tankless water heaters for appliances — such as a clothes washer or dishwater — that use a lot of hot water in your home.

Other applications for demand water heaters include the following:

  • Remote bathrooms or hot tubs
  • Booster for appliances, such as dishwashers or clothes washers
  • Booster for a solar water heating system.

What Are The Advantages and Disadvantages of Tankless Water Heaters?

For homes that use 41 gallons or less of hot water daily, tankless water heaters 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. You can achieve even greater energy savings of 27%–50% if you install a demand water heater at each hot water outlet. ENERGY STAR® estimates that a typical family can save $100 or more per year with an ENERGY STAR-qualified tankless water heater.

The initial cost of a tankless water heater is greater than that of a conventional storage water heater, but tankless water heaters will typically last longer and have lower operating and energy costs, which could offset its higher purchase price. Most tankless water heaters have a life expectancy of more than 20 years. They also have easily replaceable parts that extend their life by many more years. In contrast, storage water heaters last 10–15 years.

Tankless water heaters can avoid the standby heat losses associated with storage water heaters. However, although gas-fired tankless water heaters tend to have higher flow rates than electric ones, they can waste energy if they have a constantly burning pilot light. This can sometimes offset the elimination of standby energy losses when compared to a storage water heater. In a gas-fired storage water heater, the pilot light heats the water in the tank so the energy isn’t wasted.

The cost of operating a pilot light in a tankless water heater varies from model to model. Ask the manufacturer how much gas the pilot light uses for the model you’re considering. If you purchase a model that uses a standing pilot light, you can always turn it off when it’s not in use to save energy. Also, consider models that have an intermittent ignition device (IID) instead of a standing pilot light. This device resembles the spark ignition device on some gas kitchen ranges and ovens.​

Selecting The Best Tankless Water Heater​

Buying a tankless water heater is a huge investment and there are a few points to consider before you purchase. You need to consider:

  • Size
  • Fuel type and availability
  • Energy efficiency (energy factor)
  • Costs​

Fuel Type

The main thing to consider before you buy a tankless water heater is the type of fuel you need to decide between a Gas-fired or an Electric option. 

Location, Demand and Size

So its time to decide to buy a tankless water heater you need to think about where you will be needing hot water. Do you need hot water just in one bathroom or just on the bathroom sink? Are you looking for an entire house or apartment that needs a full water heater system? This is very important to understand the number of fixtures needed or outlet sources where you intend to have hot water. Every fixture will need its own demand of supply. Below you can see an image with the standard flow rate demand for some of the most common fixtures.

Selecting An Electric Tankless Water Heater

Planning on buying an electric water heater you need to carefully consider certain points before you start purchasing one . One of the main points to consider before you buy is the electrical requirement that they need and consume, below is a short list with detailed information to help you along the way!

  • Voltage
  • Circuit Breaker
  • Amperage

Voltage: Most retailers are selling units ranging from 110V, 120V, 208V, 220V, 240V, and 277V.

Circuit Breaker: It is advisable that your electric water heater has its dependent circuit there are much reasons for this and the main reason is safety! Please consult with a licensed electrician for help and information!

Amperage: The main point here to understand is that you must be able to support the demand of your electric tankless water heater needs in amperage as each electrical unit will have different requirements in amp draw.

Selecting A Gas Tankless Water Heater

If you prefer to buy natural gas tankless water heater you will need to consider venting requirements this is the law and for your own health. Before you start deciding on a brand you need to inspect your type of gas, is it Natural Gas or Propane? This is absolutely essential and you must ensure that you meet the standards of the new gas-fired tankless water heater. Venting is a requirement and all gas venting accessories must be Category III stainless steel (certified with UL1738 ) any other type like type B is nonacceptable.

Currently, most of the popular tankless water heater manufactures have gas venting kits and it is advisable to purchase the recommended accessories with the brand you decide to purchase with on the downside, the pre-made kits will probably not meet your house needs. Measure out your vent and the route it will take and think about where the pipe will exit out throw the nearest wall or ceiling consider all these necessary clearances. You must also consider access for air circulation then purchase venting pipes. Also, note that gas-fired tankless water heaters will still require electrical connections be sure to consider this into your plan.

FixtureLavatoryShowerBathtubKitchen SinkLaundry SinkDishwasher
Flow Rates (GPM)0.51.5 – 4.02.0 – 4.01.0 – 1.52.5 – 3.01.0 – 3.0

Tankless water heaters generate a level of water temperature based on the base flow rate of its demand this is why you need to understand how to use this table.

If you use a shower (1.5 GPM ) and also a kitchen sink ( 1.5 GPM ) at the same time you will have a demand of 3.0 GPM.

Installation and Maintenance Of Your Tankless Water Heater

Proper installation and maintenance of your demand water heater can optimize its energy efficiency.

Proper installation depends on many factors. These factors include fuel type, climate, local building code requirements, and safety issues, especially concerning the combustion of gas-fired water heaters. Therefore, it’s best to have a qualified plumbing and heating contractor install your demand water heater. Do the following when selecting a contractor:

  • Request cost estimates in writing
  • Ask for references
  • Check the company with your local Better Business Bureau
  • See if the company will obtain a local permit if necessary and understands local building codes.

If you’re determined to install your water heater yourself, first consult the manufacturer. Manufacturers usually have the necessary installation and instruction manuals. Also, contact your city or town for information about obtaining a permit, if necessary, and about local water heater installation codes.

Periodic water heater maintenance can significantly extend your water heater’s life and minimize loss of efficiency. Read your owner’s manual for specific maintenance recommendations.


There are actually a lot of advantages when you invest in buying a tankless heater over a tank water heater system but below are the positive advantages that we believe are actually the most significant in aiding you to make an informed opinion.​

Endless Supply of Hot Boiling Water 

Easily the very best reason to have a tankless water heater is actually for the endless supply of water that it provides. If you have actually ever before lacked boiling water throughout a shower, then you will certainly recognize why this is actually very crucial. Typically tankless style water heaters deliver an unlimited amount of hot water for you as the water can continuously compete so long as that it is actually needed. In a house that uses a lot of hot water, this will definitely keep the whole family happy when taking showers, one after another, without waiting for water to fill up.

Save over 40% More Money

Tankless water heaters are a lot more energy-efficient in comparison to regular tank water heaters. Installing one in your house could lead to a reduction in your electricity bill straight away, which then generally causes less money you need to spend monthly on your monthly bills. Tankless water heaters can be more expensive beforehand financially, yet throughout its daily life, the electricity cost savings should pay you back in the extra money saved and also much more as they cost less to maintain and repair.

Space Saving Smaller Units 

If you are purchasing an electric tankless water heater then you will save a great deal of additional space. Electric heaters are actually generally a 4th of the measurements of a storage-tank water heater. If the heater finds you in an interior wardrobe, that area can easily be used as additional storage the same goes for garage space imagine the space-saving you will have.

Much Less Decay and Rust 

One more advantage of tankless is actually that this is much less likely for decay and water contamination of rust. Given that the water is actually certainly not kept in the storage tank this possesses a lot less chance to rust and also contaminate the water system. Investing in a good tankless water heater generally is going to spare you the hassle of maintaining and replacing your tankless water heaters because of rust.