t’s a disaster. Your water heater is leaking and suddenly you need to buy a new one—pronto! Sure, you need to act fast, but it’s worth taking the time to consider what size of water heater is best for you.

The size you need depends on the number of bathrooms and people in your household. It also depends on whether you have a large bathtub, spa, multi-jet shower or teenagers, as they often spend a lot of time in the shower!

If you’ve been consciously conserving hot water and have installed aerators on your taps or a low-flow shower head, your consumption may be lower than average. Keep in mind, though, that a water heater lasts an average of 10 years and your needs may change over time. When purchasing a water heater, you need to think long term.

The most common water heater capacities are 40 and 60 gallons (180 and 270 litres, respectively). They also come in 20-, 80- and even 100-gallon sizes. Choosing a tank that’s too big will bump up your electricity bill, while a size too small could cause you to run out of hot water.

Here are a few things to consider when buying a water heater:


  • Generally, if you were happy with the performance of your old unit, then it was the right size for your needs. Stick to the same capacity.
  • Choosing the same size of water heater will most likely save you from having to make adjustments to your power supply.
  • Some people opt for a smaller water heater, thinking they’re being frugal consumers. Think twice: If you use hot water intensely for short periods of time (like taking showers or baths while doing laundry), a low-capacity water heater might not do the job.
  • Don’t opt for a smaller unit, thinking that it’ll shrink your energy bill. The amount of water you use will be the same, regardless of your water heater size. The only way to save is by reducing your consumption and insulating your hot water pipes.
  • If in doubt, opt for a larger size. A tank that is too small will wear out faster due to greater use.
  • Purchase a water heater that will accommodate the potential number of people in your household, not just the current number. If you plan to move, your water heater must also suit the new occupants.


Our basic recommendations:


  • Two or three people: normal consumption, 40 gallons; high consumption, 60 gallons.
  • Four or five people: normal consumption, 60 gallons; high consumption, 80 gallons.


Learn more about our Ultra Cascade water heater.