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Water heaters are a necessity in the home. They provide warm water for washing your hands, showering, cooking, and cleaning. To do this, the cold water comes from a water supply pipe and then it warms it up. Then, it is pumped through the home when the water is turned on. A tankless water heater is a type of water heating system that does not require a storage tank, unlike traditional water heaters. It provides hot water on demand, eliminating the need for storing and constantly reheating water. Are tankless water heaters gas or electric? They are available in both gas or electric and it depends on the type that you choose. There are advantages and disadvantages to both.

Let’s learn more about tankless water heaters.

Tankless water heaters can be electric or gas.

What is a Tankless Water Heater?

A tankless water heater, also known as an instantaneous or on-demand water heater, heats water directly as it passes through the unit. Unlike traditional water heaters that store and constantly heat a large amount of water, tankless water heaters only heat water when you need it.

How Do Tankless Water Heaters Work?

Tankless water heaters work by using high-powered burners or electric coils to rapidly heat the water as it flows through the unit. When you turn on the hot water tap, sensors in the heater detect the flow and activate the heating element. The water then passes through the heat exchanger, where it is quickly heated to the desired temperature before being delivered to your faucet or shower.

Advantages of Tankless Water Heaters

There are several advantages to using a tankless water heater:

  • Energy efficiency: Tankless water heaters only heat water as it is needed, resulting in significant energy savings compared to traditional water heaters.
  • Endless hot water: With a tankless water heater, you never have to worry about running out of hot water, as it is continuously heated on demand.
  • Space-saving design: Tankless water heaters are compact and can be installed in tight spaces, freeing up valuable floor space.
  • Longer lifespan: Tankless water heaters typically have a longer lifespan than traditional water heaters, lasting up to 20 years or more with proper maintenance.

Disadvantages of Tankless Water Heaters

Despite their advantages, tankless water heaters also have some drawbacks to consider:

  • Higher initial cost: Tankless water heaters tend to have a higher upfront cost compared to traditional water heaters.
  • Limited flow rate: A single tankless water heater may struggle to supply hot water to multiple fixtures simultaneously, especially in larger households.
  • Complex installation: Installing a tankless water heater often requires modifications to your home’s plumbing and electrical systems, which can make the process more complicated and expensive.

What to Consider When Selecting a Tankless Water Heater?

When choosing a tankless water heater, there are several factors to consider:

  • Flow rate and capacity: Determine the maximum hot water flow rate you will need, taking into account the number of fixtures you intend to use simultaneously.
  • Fuel type: Tankless water heaters can be powered by either gas or electricity. Consider which fuel type best suits your needs and availability.
  • Energy efficiency: Look for energy-efficient models with high-efficiency ratings to maximize your energy savings.
  • Size and installation requirements: Ensure that the tankless water heater you choose will fit in the available space and meet any installation requirements.
Gas tankless water heater

Are Tankless Water Heaters Gas or Electric?

Tankless water heaters can be powered by either gas or electricity, depending on the model and your preference. Gas tankless water heaters use natural gas or propane to heat the water, while electric tankless water heaters rely on electric heating elements.

What to Consider When Selecting a Tankless Water Heater

When choosing a tankless water heater, several factors should be taken into consideration:

  1. Desired flow rate: Determine the maximum amount of hot water needed at peak times, such as during simultaneous showers or appliance usage.
  2. Energy source availability: Consider whether gas or electric power is readily available in your area and choose a tankless water heater that matches the energy source.
  3. Size and space limitations: Ensure that the chosen tankless water heater fits the available space for installation.
  4. Warranty and maintenance requirements: Look for a tankless water heater with a reliable warranty and consider the maintenance requirements for optimal performance.

Gas Versus Electric Tankless Water Heater

There are two main types of tankless water heaters: gas-powered and electric-powered. Each has its advantages and considerations:

Gas tankless water heaters:

These units use natural gas or propane as their fuel source. They typically have a higher flow rate, making them suitable for larger households with high hot water demand. However, they require proper ventilation and regular gas line maintenance.

Electric tankless water heaters:

These units rely on electrical heating elements to heat water. They are generally more compact and easier to install than gas units. However, they may have lower flow rates and could be less efficient in areas with high electricity costs.

How Do Tankless Water Heaters Heat Water?

Tankless water heaters heat water through different methods based on their energy source:

  1. Gas tankless water heaters: These units use burners fueled by natural gas or propane. When the hot water tap is turned on, the burners ignite to heat the heat exchanger, which then heats the passing water.
  2. Electric tankless water heaters: These units use electric heating elements that heat up when the hot water tap is opened. As water flows over these elements, it gets heated before being delivered to the faucet or showerhead.

Cost of Electric and Gas Water Heaters

The cost of tankless water heaters can vary depending on their size, features, and energy source. Generally, gas tankless water heaters are more expensive than electric ones due to the complexity of their installation and the need for proper ventilation. The price range is $1000 to $4000 with an average of about $2500 (October 2023). A standard water heater costs between $850- $1700 depending on the size (Nov. 2023).

Are Electric or Gas Water Heaters More Energy Efficient?

Both electric and gas tankless water heaters can be energy-efficient when compared to traditional storage tank water heaters. However, gas tankless water heaters tend to have higher energy efficiency ratings due to the lower cost of natural gas compared to electricity.

How to Improve Energy Efficiency

To further improve the energy efficiency of a tankless water heater, consider the following tips:

  1. Lower the water temperature: Adjusting the water temperature to a lower setting reduces energy consumption.
  2. Insulate hot water pipes: Insulating pipes prevent heat loss as water travels from the tankless water heater to the faucets. This reduces the need to reheat water.
  3. Install low-flow fixtures: Low-flow faucets and showerheads reduce hot water usage without sacrificing comfort.
  4. Regular maintenance: Keeping the tankless water heater clean and performing regular maintenance, such as descaling, ensures optimal performance and efficiency.

Now you know about electric and gas tankless water heaters, but there are some things you may not know about them. Check out the video below.

Other Recommended Maintenance

Now that you know about tankless water heaters, there are a few areas of recommended maintenance. One of those is why your tankless water heater may be leaking. This tends to happen if there are poor plumbing connections. Water flows through the pipes and then the connections can leak. It is important to have your plumbing checked regularly.

Another is flushing a tankless water heater. Over time, mineral deposits build up and lower its performance. Thus, it is necessary to flush the water heater and you can do this by following the steps.

Lastly, if you have a traditional water heater and haven’t switched to tankless yet, how long does it take to heat up? It will depend on the type of water heater you have and also

When Do I Call a Professional?

We recommend you call a professional plumber or HVAC technician in the following situations:

  1. Installation: If you are unsure about the installation process or need assistance with modifying your plumbing or electrical systems, it is best to seek professional help.
  2. Repairs: If your tankless water heater is not functioning properly or requires repairs, a professional can diagnose and fix any issues safely.
  3. Maintenance: Professional technicians can perform routine maintenance tasks, such as descaling and checking for potential issues, to keep your tankless water heater running efficiently.

Also, it is always a good idea to have your water tested. Reach out to Enviroquest and we can do that for you!


Tankless water heaters offer numerous benefits, including energy efficiency, space-saving design, and continuous hot water supply. However, they also have some drawbacks, such as higher upfront costs and potential installation complexities. Consider your specific needs, energy source availability, and space limitations when selecting a tankless water heater. Seeking professional assistance can ensure proper installation, repairs, and maintenance of your tankless water heater. While you are looking at the installation of a tankless water heater, this is a good time to reach out to Enviroquest Home Inspections for a complete home inspection in Harrisburg, PA.

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