Tankless Water Heater for One Bathroom

When it comes to providing hot water efficiently, tankless water heaters have become increasingly popular in recent years. Their compact size, energy-saving features, and on-demand hot water supply make them an excellent option for small households.

In this guide, we will explore the benefits of tankless water heaters and provide you with valuable insights to help you choose the perfect one for your single-bathroom household.

Understanding Tankless Water Heaters

What is a Tankless Water Heater?

A tankless water heater, also known as an instantaneous or on-demand water heater, is a system that heats water on the spot as it passes through the unit. Unlike traditional water heaters that store and heat a large volume of water, tankless units provide hot water instantly when needed, eliminating the need for a bulky storage tank.

How Do Tankless Water Heaters Work?

Tankless water heaters use either electric elements or gas burners to heat water as it flows through a heat exchanger. When a hot water tap is turned on, cold water enters the unit and passes through the heat exchanger, where it is rapidly heated to the desired temperature before exiting the unit and reaching the tap.

Advantages of Tankless Water Heaters

  • Energy Efficiency: Tankless water heaters only heat water when it is needed, resulting in significant energy savings compared to traditional storage tank systems.
  • Space Savings: Tankless units are significantly smaller than storage tank systems, making them ideal for small homes or apartments with limited space.
  • Endless Hot Water: With a tankless water heater, you don’t need to worry about running out of hot water, as it is supplied on demand for as long as needed.

Sizing a Tankless Water Heater for One Bathroom

Determining the Flow Rate

The flow rate of a tankless water heater indicates the amount of hot water it can supply per minute. To determine the required flow rate for a single bathroom, you need to consider the following factors:

  • Number of fixtures: Count the number of showers, sinks, and other water fixtures in your bathroom that are likely to operate simultaneously.
  • Flow rate per fixture: Each fixture has a specific flow rate, which is usually indicated on the product label or can be found in the manufacturer’s specifications.
  • Temperature rise: Calculate the temperature difference between the incoming cold water and the desired hot water temperature. The colder the climate, the greater the temperature rise required.

Choosing the Right Size

Once you have determined the flow rate required for your bathroom, you can select a tankless water heater that meets your needs. It’s crucial to consider the unit’s maximum flow rate and temperature rise capabilities to ensure it can supply adequate hot water to all fixtures. Larger units with higher flow rates are typically more suitable for households with multiple bathrooms or high hot water demand.

Gas vs. Electric Tankless Water Heaters

Gas Tankless Water Heaters

Gas tankless water heaters are powered by natural gas or propane, making them an excellent option for homes with an existing gas supply. They offer higher flow rates and are generally more energy efficient than electric models. However, gas units require proper ventilation and produce combustion gases that must be vented safely.

Electric Tankless Water Heaters

Electric tankless water heaters are powered by electricity and do not emit any combustion gases. They are more compact and easier to install than gas units. However, electric models may have limitations in terms of flow rate and may require an upgraded electrical service panel to accommodate their high power demands.

Installation Considerations


When selecting a tankless water heater for one bathroom, consider the most suitable location for installation. Tankless units can be mounted on the wall, saving valuable floor space in small bathrooms. Ensure the chosen location allows for proper venting (if using a gas unit) and easy access for maintenance and service.

Plumbing Connections

Before purchasing a tankless water heater, it is essential to ensure that your existing plumbing connections are compatible with the unit’s specifications. Verify the required pipe size, water pressure, and any specific installation requirements specified by the manufacturer.

Professional Installation

While some homeowners may be comfortable with DIY installations, it is highly recommended to hire a professional plumber or technician for a proper tankless water heater installation. They will ensure proper ventilation, gas connections (if applicable), and optimal placement for efficient operation.

Maintenance and Service

Flushing the Unit

To maintain the performance and longevity of your tankless water heater, regular flushing is recommended. Over time, mineral deposits and sediment can accumulate in the heat exchanger, reducing efficiency. Flushing the unit annually helps remove these deposits and keeps the system operating optimally.

Filter Cleaning

Some tankless water heaters are equipped with a filter to prevent debris from entering the heat exchanger. Regular cleaning of this filter is necessary to ensure uninterrupted water flow and prevent damage to the unit.

Annual Maintenance Check

Schedule an annual maintenance check by a professional technician to inspect the unit, clean components, and verify its proper functioning. This proactive approach can help identify any potential issues before they turn into major problems.


Are tankless water heaters more expensive than traditional ones?

No, tankless water heaters may have a higher initial cost, but they can save you money in the long run due to their higher energy efficiency and longer lifespan.

Can a tankless water heater supply hot water to multiple fixtures simultaneously?

Yes, tankless water heaters are designed to supply hot water to multiple fixtures simultaneously, depending on their flow rates and the unit’s capacity to meet the demand.

Do tankless water heaters require regular maintenance?

Yes, tankless water heaters require regular maintenance, such as flushing the unit and cleaning filters, to ensure optimal performance and prolong their lifespan.

Do tankless water heaters work well in cold climates?

Yes, tankless water heaters perform well in cold climates. However, the temperature rise required to reach the desired hot water temperature may be higher, potentially impacting the unit’s flow rate.

Can I install a tankless water heater by myself?

While it is possible to install a tankless water heater yourself, it is recommended to hire a professional plumber or technician for proper installation to ensure safety and optimal performance.


Choosing the right tankless water heater for your one-bathroom household is an important decision that requires careful consideration of various factors.

By understanding your hot water needs, sizing requirements, and the differences between gas and electric units, you can make an informed choice. Remember to prioritize professional installation and regular maintenance to ensure your tankless water heater operates efficiently for years to come.

Leave a Reply

Your email address will not be published. Required fields are marked *