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Gas-fired storage water heaters - household

Energy Efficiency Regulations

Regulatory definition

Household gas-fired storage water heater, a stationary gas-heated water container that uses propane or natural gas for fuel, has a Vr of at least 76 L (20 US gallons) and has an input rate of less than or equal to 21.97 kW (75,000 Btu/h).

Compliance date

Manufactured on or after January 1, 2018

For models manufactured prior, refer to the Regulations

Compliant product models

Gas-fired storage water heaters - household as listed on NRCan’s searchable database

Testing standard

CSA P.3-04 for energy factor

CSA P.3-15 for uniform energy factor

Energy efficiency regulations by province

Some provinces also have their own energy efficiency regulations for many of the federally regulated products – find out which ones!

Energy efficiency standard

Energy performance standard for household gas-fired storage water heaters

If the First-hour rating is: Energy factor Uniform energy factor

˂ 68 L (18 US gallons)

Tested to the very small draw pattern

≥ 0.675 – 0.00039 Vr

≥ 0.3456 – 0.00053 Vs

≥ 68 L (18 US gallons) but ˂ 193 L (51 gallons)

Tested to the low draw pattern

≥ 0.675 – 0.00039 Vr

≥ 0.5982 – 0.00050 Vs

≥ 193 L (51 gallons) but < 284 L ˂ (75 US gallons)

Tested to the medium draw pattern

≥ 0.675 – 0.00039 Vr

≥ 0.6483 – 0.00045 Vs

˃ 284 L (75 US gallons)

Tested to the high draw pattern

≥ 0.675 – 0.00039 Vr

≥ 0.692 – 0.00034 Vs

L = Litres
Vr = the rated nominal volume, typically used in marketing material
Vs = the measured storage volume as defined in the testing standard


A model tested using CSA P.3-04 must only submit their Energy Factor (EF) value.

A model tested using CSA P.3-15 must only submit their Uniform Energy Factor (UEF) value.

The Minimum Energy Performance Standard (MEPS) formulae are equivalent in terms of energy performance, even though they may result in a different number. This is due to the parameters of the different testing standards.

A specific conversion equation must be used to make an acceptable comparison between EF values and UEF values.

Models tested using one specific UEF draw pattern cannot be compared to another model of a different UEF draw pattern.

Energy efficiency report requirements

  • name of product
  • brand name
  • model number
  • manufacturer
  • the name of the certification body or province whose verification mark will be on the product or its package
  • whether a mathematical model as defined in the Regulations was used to generate any of the information provided below
  • input rate, in kW (Btu/h)
  • recovery efficiency
  • type of fuel used
  • annual energy consumption, in kJ
  • first-hour rating, in L
  • Vr
  • Vs
  • energy factor
  • uniform energy factor

Download the energy efficiency reporting template.

This document does not constitute part of the Energy Efficiency Act (Act) or its associated regulations.  This document is an administrative document that is intended to facilitate compliance by the regulated party with the Act and its associated regulations.  This document is not intended to provide legal advice regarding the interpretation of the Act or its associated regulations. If a regulated party has questions about their legal obligations or responsibilities under the Act or its associated regulations, they should seek the advice of legal counsel.

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