How to Choose a Natural Gas Water Heater

Tank size

In choosing a new natural gas water heater, you need to consider the size of the tank. If your current water heater is unable to provide enough hot water, you may want to consider a larger tank. If you are replacing an electric water heater, keep in mind that a natural gas water heater recovers, or reaches the set temperature, in half the time.

Consult the chart below to help you decide what tank size best meets your needs:

Tank Size Guide

House Type

Family Size*

Peak Daily
Water Use
(Litres)

Tank Size
(U.S. Gallons)

Tank Size
(Litres)

Vacation cottage or
very small family
home

2-3

190

20

75

Small family home

3

227

30

114

Home with 2 bathrooms,
3 bedrooms and
washing machine

3-4

454

40

151

Home with 3 bedrooms,
washing machine and
dishwasher

4-5

568

40

151

Home with 4 bedrooms,
washing machine and
dishwasher

4-6

621

50

189

Larger home with 4 or
more bedrooms, washing
machine and dishwasher
(heavy use characteristics)

5-7

757

60

227

Larger home as above
with whirlpool baths

6-8

946

75

291

* If teenagers are in the home, select one model size larger.

 

 

Conventional vent

Consider this option if:

  • You currently have a natural gas water heater with a conventional vent.

  • You want to place the new water heater in the same location and use the same vent system -- the chimney, for example.


              

Power vent

Consider this option if:

  • You cannot use, or do not want to use, a chimney -- when replacing an existing electric water heater, for example.

  • The water heater does not have to be located close to an exterior wall

Direct vent

Consider this option if:

  • You cannot use, or do not want to use, a chimney -- when replacing an existing electric water heater, for example.

  • The water heater can be located close to an exterior wall and an 8-inch hole can be drilled in the wall.

  • No electricity is required, which means there is no need for a 110-volt receptacle.

Professional Installation

With power vent and direct vent models, the outdoor vent termination is important. If the vent terminates outside, you need to have a licensed contractor perform an "onsite measure."

Outdoor venting examples that require an onsite measure:

  • under a deck or a porch
  • less than one foot above grade level
  • near a public walkway
  • near a window
  • near a door
  • near a gas meter