top of page

Hot Water Tanks vs. Tankless Systems: Making an Informed Decision

Updated: May 24

When it comes to providing hot water for your home, there are two primary options to consider: hot water tanks (also known as storage tank water heaters) and tankless (on-demand) systems. With over 30 years of experience in the heating, ventilation, and air conditioning business, Rodger That Heating & Cooling is well-equipped to guide homeowners through the decision-making process and help them choose the right hot water solution for their needs.

Hot water tanks and tankless systems each come with their own set of advantages and drawbacks, depending on factors such as energy efficiency, hot water demand, installation costs, and space requirements. It is crucial for homeowners to understand the fundamental differences between these two options in order to make an informed decision that will best serve their needs, both now and in the future.

How They Work: Decoding Hot Water Systems

The first step in determining the ideal hot water system for your home is to understand how each option operates. Traditional hot water tanks function by storing and heating a large volume of water, typically between 151 to 378 litres (40 to 100 gallons), within an insulated tank. As hot water is used, it is replenished with cold water and heated to the desired temperature. This storage and constant heating mechanism ensures that there is a substantial supply of hot water readily available.

Alternatively, tankless systems, also known as on-demand systems or instantaneous water heaters, heat water as it flows through the unit, providing hot water only when needed. They do not require a storage tank; instead, they use high-powered burners or electric elements to heat the water as it passes through a heat exchanger. This results in an endless supply of hot water, but with certain limitations regarding the flow rate.

Energy Efficiency: Assessing Performance and Costs

In terms of energy efficiency, tankless systems tend to outperform traditional hot water tanks. With tankless systems, there is no standby heat loss, as water is only heated when required, which can lead to significant energy savings and reduced utility bills. According to Natural Resources Canada, tankless water heaters are approximately 22% more energy efficient on average compared to conventional storage tank water heaters.

However, it is important to consider that the upfront costs of installing a tankless system are generally higher than those associated with hot water tanks. Factors such as the cost of the unit, necessary venting upgrades, and potential electrical modifications can contribute to these increased expenses. As a result, homeowners need to balance the potential for long-term energy savings against the upfront costs of installation.

Hot Water Demand: Meeting Your Household's Needs

Another crucial factor to consider when choosing a hot water system is its ability to meet your home's hot water demands, particularly during periods of high usage. Hot water tanks typically have a lower flow rate than tankless systems, but their large storage capacity allows them to provide a substantial supply of hot water for simultaneous use by multiple fixtures.

In contrast, tankless systems may struggle to provide an adequate supply of hot water when multiple fixtures are in use simultaneously, particularly if the unit is not adequately sized for the home's needs. It's essential to consult with a professional to accurately assess your home's hot water demand and determine the appropriate size and type of system to meet those requirements.

Installation and Maintenance: Costs, Space, and Lifespan

Before committing to a hot water system, it's necessary to weigh the various installation and maintenance factors that come with each option. Traditional hot water tanks tend to have lower installation costs, but they can also require more space due to their sizeable storage tanks. Furthermore, hot water tanks typically have a lifespan of 10 to 15 years, which is shorter than tankless systems, which can last 20 years or more with proper maintenance.

On the other hand, tankless systems have a smaller footprint, making them ideal for homeowners with limited space or those interested in a minimalist aesthetic. Additionally, they often have longer warranties and lifespans, which can help compensate for the higher upfront costs. However, tankless systems may require more frequent maintenance, such as flushing, to prevent scale buildup and maintain optimal performance.


The decision between a hot water tank and a tankless system should be based on an evaluation of factors such as energy efficiency, hot water demand, installation and maintenance costs, and available space. By considering these factors and understanding the fundamental differences between the two options, homeowners can make an informed decision on which system best meets their needs.

For top-notch HVAC residential services, reach out to Rodger That Heating & Cooling. We recognize the significance of choosing the ideal hot water solution for your residence. Contact us now to arrange a consultation, during which our seasoned professionals will assist you in evaluating hot water tanks and tankless systems. With our expertise, you can make a confident decision that perfectly suits your lifestyle, budget, and home comfort needs.

1 view0 comments


bottom of page