Types of Water Heaters

There are 3 types of natural gas water heaters. Choose the best system for your household needs, to ensure sufficient hot water while maximizing energy efficiency.

Water heater types

Storage Tank

Water HeaterCold water is heated and stored in a tank, ready to use anytime. Consists of a steel storage tank that holds 113 to 378 litres and a gas burner.


  • Very simple and relatively inexpensive system that uses little or no electricity.
  • Recovers hot water about two times faster than a same-size electric tank.

How it works:

  • Cold water is drawn into the bottom of the tank where it’s quickly heated by a gas burner. Heated water is stored in the tank and reheated until needed.
  • The tank thermostat controls the water temperature sent to your taps.

Tankless Water Heater

Tankless systems heat water on demand. The units don't store hot water and are so small they can be hung on a wall. As water flows through the unit's heat exchanger, it's rapidly heated to the desired temperature. 

Tankless Water Heater

Tankless units are significantly more expensive to buy and complicated to install. Users may also notice a "lag time" between when a tap is turned on and the hot water starts flowing out of the tap.


  • Endless supply of hot water.
  • Efficiency rate of 80 per cent or higher. Pay only when you use hot water, usually two hours a day, instead of heating a tank of hot water all day.
  • Space-saver since there is no storage tank. Wall-mounted units are small and can be hung on almost any wall, including close to the point of use.

How it works

  • When a hot water tap is turned on, cold water travels through a pipe through the water heater unit and is rapidly heated to the desired temperature.
  • When the tap is turned off, the system shuts down and uses no energy.

Combination Water and Space Heating

Combination systems use a single natural gas water heater to provide both heat and hot water to your home. High-efficiency systems usually include a high-efficiency storage tank or tankless water heater.


  • Energy-efficient – reduces energy use.
  • Space-saver since there is no furnace.
  • Cost savings – lower on-going maintenance and operating costs since there is no furnace, although installation cost is higher.

How it works

  • Combo radiant floor heating: Warms from the floor up, utilizing hot water circulating through a network of plastic tubing embedded in concrete floors.
  • Combo hydronic baseboards: A direct replacement for electric baseboards. Hot water from the natural gas hot water tank is piped directly to each baseboard.
  • Combo fan coil and forced air: Uses existing duct work to distribute the heat recovered from the hot water tank. Electronic air cleaners, humidifiers, and air-conditioners can be used with this system.

Depending on your current water heating system, you may need to update the venting system when changing your water heater.