Tank vs. Tankless Water Heater: Which Should You Choose?
Published on December 9, 2025
Tank or tankless? Both options can meet a home’s hot water needs, but they do not necessarily suit the same priorities.
Available space, upfront cost, hot water use and lifespan: here are the main differences to consider when choosing the right water heater for your home.
Tank water heater
It may be a better fit if you are looking for:
- a generally lower upfront cost;
- a well-known technology;
- different capacities to suit your household’s needs.
Things to consider:
- it requires more space;
- the amount of hot water available depends on the size of the tank;
- water must be kept hot even when it is not being used.
Typical lifespan: 10 to 15 years.
Tankless water heater
It may be a better fit if you are looking for:
- a compact unit;
- on-demand operation;
- fewer energy losses associated with keeping stored water hot;
- a generally longer lifespan.
Things to consider:
- its upfront cost is generally higher;
- the unit must be selected based on your household’s actual hot water needs.
Its lifespan can reach 20 years or more.
Tank or tankless: compare the essentials
| Tank water heater | Tankless water heater | |
|---|---|---|
| Operation | Water is heated and stored in a tank. | Water is heated when it is needed. |
| Space required | More space required. | Compact and generally wall-mounted. |
| Upfront cost | Generally lower. | Generally higher. |
| Hot water availability | Depends on tank capacity. | Depends on the unit’s capacity. |
| Keeps water hot | Yes. | No. |
| Lifespan | About 10 to 15 years. | Can reach 20 years or more. |
Performance and lifespan may vary depending on the unit, installation, use and maintenance.
Which model best fits your needs?
Rather than choosing based on technology alone, start with how you use hot water at home.
Are you short on space?
A tank water heater requires dedicated space. If space is limited, the compact design of a tankless model may be an advantage.
How much hot water do you use?
The number of people in your household, back-to-back showers and the simultaneous use of several appliances can all affect hot water demand.
With a tankless water heater, it is especially important to choose a unit that can meet that demand.
What is your budget?
A tank water heater is generally more affordable to purchase.
A tankless model usually requires a larger upfront investment but generally offers a longer lifespan. Looking at the cost over the full life cycle of the unit, rather than the purchase price alone, can therefore be useful.
Thinking about switching to tankless?
Enbridge Gaz Québec offers a $500 rebate to eligible customers who replace their tank water heater with a tankless model.
What about buying or renting?
Choosing between a tank and tankless water heater is one decision. Once you have selected the technology that suits your needs, you can then decide how you want to get your unit.
Buying or renting a water heater: which option should you choose?
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