Tankless water heaters

Looking for an energy-efficient tankless water heater?

In Canada, tankless water heaters:

  • display the ENERGY STAR® symbol if the model qualifies as high efficiency

Detailed information for manufacturers

Additional information for retailers


A tankless water heater goes by many names: it is sometimes called an on-demand, an instantaneous or a point-of-use water heater. It has no storage tank and heats flowing water only when required, using either an electric element or a gas burner.

Tankless water heater technology and energy efficiency

A tankless water heater is usually more energy efficient than a storage tank water heater. It eliminates the continuous standby energy loss of a storage tank.

Tankless water heaters are rated with an energy factor (EF): the higher the EF, the more efficient the water heater.

Gas tankless water heaters have EFs that range from 0.64 to 0.98, with an average of 0.85. Gas storage tank water heaters have EFs that range from 0.53 to 0.70, with an average of 0.62.

Gas tankless water heaters have the capacity to supply hot water for most houses.

Most electric tankless water heaters cannot supply an entire house with hot water. They are most effective when installed as supplementary heaters near bathroom or kitchen sinks far from the main water heater. They are also useful in locations with few fixtures and less demand for hot water, such as in a workshop or cottage.

Savvy shoppers check the “second price tag”

A tankless water heater’s first price tag—the sticker price and installation costs—is quite a bit higher than a conventional storage tank heater. The “second price tag” is the cost of operating the product over its lifetime and tankless water heaters can save at least 30 percent in energy costs compared to a conventional storage tank heater.

Buy ENERGY STAR for high efficiency

Energy Star logo

Make shopping easy: look for the ENERGY STAR symbol.

Products that qualify for the symbol are the best energy performers of all makes and models on the mainstream market. They meet strict technical specifications for high efficiency—without compromising features or performance in other areas.

Compare current models of tankless water heaters available in Canada using our searchable product list.

For a practical overview, read our Water Heater Guide [PDF - 2.8 MB].


The ENERGY STAR name and symbol are administered and promoted in Canada by Natural Resources Canada and are registered in Canada by the United States Environmental Protection Agency