Can Tankless Water Heaters Keep Up With Demand

The concept of a Tankless Water Heater generated from the idea of creating hot water without the need to store it in a tank and waste energy constantly reheating the water. It is a push and get solution, turn on the tap and the water coming through the line nearly instantly converts into the given temperature. Hence, this saves gas and electricity energy immensely.

Every buyer is interested in finding out how tankless water heaters work and what is the mechanics behind a tankless system conforming to supply and demand of a household. Let’s unfold these basic and most frequently asked queries followed by some tips for choosing the right tankless water heater.

Tankless Water Heating System

There are multiple websites that have information about how tankless water heaters work. We would like to explain it here in the most simplistic and easy to understand manner that would solve all questions regarding tankless water heatings functions in one go-

  • Heat Exchangers Installed For Instant Hot Water

If you have a conventional water heater installed right now, take a look at it, it is holding certain amount of water, continually heating it a temperature that you would need for your next shower, say 2 hours from now. Heating water on an on-going basis for 2 hours until it is used, leads to wastage of energy.

To combat this wastage of gas or electricity, heat exchangers are installed in the tankless water heating system. As soon as a tap is turned on, water pulls from its source in its original temperature, the heat exchanger converts it into the desired hot temperature, and you instantly get hot water to your tap! The exchanger remains on standby the whole while, it activates only when water passes through the system. It is extremely user-friendly and easy to comprehend.

The exchanger is the main component to a tankless water heater and is what saves you money on energy, since it only activates when it is needed.

  • Point-Of-Use Or Whole-House Heating Solution According to Consumption

Tankless water heaters, thus, provide hot water through its electric coil or gas-fired burner (heat exchanger) which converts the temperature of water as it passes through. To meet the varying demands of consumption, tankless water heaters come in two categories- Point of Use and Whole House.

Point of Use water heating systems are for lesser usage, such as the kitchen tap or one other outlet at max. This category is handy, compact and easy to install. Due to it’s small size, it can be fixed anywhere near the kitchen tap which would reduce the lag time- interval between tap being turned on and water flowing. On the contrary, if more than two sources of water consumption need to be catered with higher consumption, Whole-House Tankless Water Heating Solutions are better.

Tankless Water Heating System Supply & Demand

From the many uses that Tankless Water Heating System comes in a household includes bathroom usage, hot tubs, washing machines for clothes, dishwashers and kitchen usage. Even if it is a nuclear family, but having 4 to 5 family members, chances are two or more people are going to need hot water at the same day during the day (don’t forget about showers, dishwashers, etc!).

Typically, most tankless water heating systems are designed to provide approximately 2 to 5 gallons of hot water per minute (GPM). This supply rate may definitely be sufficient for smaller family demands, but for larger ones, it is essential to either choose a gas lit water heater or install more than one water heaters.

For a greater understanding on how tankless water heaters supply hot water and which water heater would be the best to choose according to household needs, read the information given below.

  • Factors that Determine Supply Rate of Tankless Water Heaters According to Demand

The features in a tankless water heater that determine its capability of providing hot water include the size of the water heater that is being purchased, along with its fuel capacity and availability coupled with its cost. Opting for a sustainable fuel source such as gas instead of electricity would be better and environment friendly. As for the cost, the installation and buying budget that one has points out to the average GPM that is delivered by the water heating system.

Always check the GPM of the tankless water heater to understand its supply ability. Here’s a small example that would aid in the process of understanding how GPM works. For instance, the temperature of groundwater is 35 degrees, and the required temperature for a hot bath is 103 degrees, so the difference of 103-35= 68 degrees is the required rise that the Tankless Water Heater must be able to provide. Thus, choose at least a GPM converter that is suitable for a 68 degrees hike. If the GPM of a tankless water heater is 2.2 GPM and the shower head of the bathroom exits 5 GPM then it would be insufficient, even if the latest style shower head of 2.2 GPM is installed, the tankless water heater would be insufficient as it would mean that while hot water is being used in the bathroom it cannot be used in any other secondary source.

Therefore, one must be able to first calculate flow rate or amount of water that needs to be heated at one time and then compare it with the GPM offering of the Tankless Water Heater, this is the main source of making sure if the heating solution is capable of fulfilling demands of a household or not. For more detailed description of flow rate calculation per tap and room’s usage, visit Therefore, tankless water heaters are capable of fulfilling varying demands of a household, depending on which model has been chosen.










Electric Vs Gas Tankless Water Heaters

Tankless water heaters are somewhat new in America but have been popular in Japan and Europe for several years. These tankless (or on-demand) water heaters heat water only as it’s needed, thereby eliminating the energy loss associated with your conventional hot water heater which periodically heats up water contained in a tank throughout the day to maintain its temperature.

These heaters also are capable of producing unlimited hot water because of the way they work. Instead of heating a set amount of water in a tank, the water is rapidly heated only when you turn on the hot water, so it can continuously supply your home with precisely heated water. But through what function is the water heated?

Deciding on a Tankless Water Heater

Tankless water heaters use a powerful heat exchanger to rapidly heat the incoming water. A heat exchanger is any kind of device that transfers heat to another substance. Obviously this heat exchanger must be powered by something, and in hot water heaters it is typically either through electricity or natural gas. Over at, they have a great guide on how exactly these heat exchangers work if you are interested.

Which type of heater you decide on rests on several important factors:

  • The accessibility to a source of natural gas or an electrical power supply that is of adequate power
  • Your budget
  • Household water demands
  • Installation Location

Electric Tankless Heaters

inside of an electric tankless water heater

One huge benefit of electric heaters is that they cost less to purchase. A typical electric heater can run you anywhere from $200 – $500 while a propane powered heater could cost you anywhere from $500 to $1000. Higher quality natural gas heaters can cost even more than that, depending on their build quality and presence of electronic ignition systems.

Another plus that comes along with electric heaters are their incredible efficiency. Most have an energy efficiency of 98 – 99%, meaning virtually all the energy they use is going directly to heating water, with none lost. Compare that to the 80 – 85% you would get with a gas powered tankless heater and you start to see where it could add up.

Electric models also tend to be much easier to install, only taking up about a third of the size of the space of a gas powered heater. Many are about the size of a VCR or Webster’s dictionary! Gas models also tend to require complex venting solutions to get rid of gases produced while heating water. This could make installation more expensive and difficult depending on your situation. Contact a professional contractor for verification.

Electric heaters also have the benefit of not needing as much maintenance. They are more than happy to sit alone in your basement churning out hot water for years while you forget about them. On the other hand, gas heaters will need an annual inspection to ensure safety for you and your family. Electric units also tend to be simpler, making them easier to troubleshoot and fix.

Gas Powered Heaters

gas powered tankless water heater

That being said, gas tankless water heaters have their upside as well. The gas models are often capable of outputting much more water, with many reaching 10 gallons per minute in the proper conditions. This makes these heaters well suited to a larger household where there could be a dishwasher, washing machine, shower and faucet going all at once.

Electric heaters also tend to require very high electricity needs, and many times the breaker in your home will not cut it. In colder climates (because it takes more energy to heat colder water), you will often need at least a 200 AMP and 208 to 240 electrical service to run them. It is more common for there to be a gas line of some sort already in the location where you want to install the heater, which  could make installation a bit easier.

Final Decision

Ultimately, the decision is yours when it comes to which water heater to purchase. Accomodations will probably need to be made when it comes to installing each heater and electric models have been increasing their GPM steadily. Overall, most home owners find the low cost and low maintenance of the electric heaters to be preferable and, for most homes, they provide more than an adequate amount of hot water. I would recommend an electric tankless water heater for most homes, unless you live in a very cold climate or have very high water useage.

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