Instantaneous water heaters – March 2017

Technical bulletin on developing the standards

Please note: This bulletin is out-of-date. Stakeholders should visit the Amendment 15 page for the most recent developments.

Webinar – April 2017

On March 4, 2017, Natural Resources Canada's Office of Energy Efficiency issued a Notice of Intent to amend Canada’s Energy Efficiency Regulations (the Regulations) to adopt standards for instantaneous water heaters, also called tankless water heaters. This technical bulletin has been released to initiate the consultation process and to collect stakeholder views on the requirements being considered for instantaneous water heaters.

Input received during this stage of the process will inform the development of the Amendment 15 proposal. In addition, the department will undertake a cost-benefit analysis using the best-available Canadian market data to assess the economic and environmental impacts of these new standards and to ensure Canadian consumers and businesses benefit from their implementation.

The Government of Canada intends to pre-publish a regulatory proposal in the Canada Gazette, Part I, within approximately two years of this bulletin.


Through the Pan Canadian Framework and Energy and Mines Minister’s Conference the federal, provincial and territorial governments have committed to working together to achieve climate change goals. Through this collaboration, governments agreed that standards for some space and water heating products, such as instantaneous water heaters could, for climatic and market reasons, exceed the stringency of those in the U.S.

Instantaneous water heaters are not currently an energy using product. Natural Resources Canada (NRCan) is considering introducing Minimum Energy Performance Standards (MEPS) for instantaneous water heaters. NRCan’s preliminary assessment of the market shows that all instantaneous water heaters shipped in Canada are at or above the current United States Department of Energy (U.S. DOE) level of 0.82 Energy Factor (EF). Further, almost 75% of all instantaneous water heater shipments in Canada are at or above the condensing level of 0.90 EF. Given that there are no instantaneous water heaters in Canada below the U.S. DOE level, NRCan is considering proposing MEPS at the condensing level, to achieve greater energy savings and greenhouse gas emissions reductions.

In 2015, the Canadian Standards Association (CSA), with support from various partners and NRCan, harmonized the CSA water heater test standard to the new DOE version that was finalized in 2014. This updated CSA P.3-15 - Testing method for measuring energy consumption and determining efficiencies of gas-fired and fuel oil-fired water heaters introduced a new metric, the Uniform Energy Factor (UEF), and increased the scope of the test procedure to include oil-fired water heaters and instantaneous water heaters. The UEF metric rates water heaters according to their capacity to deliver hot water. For instantaneous water heaters, the maximum flow rate determines the test standard’s draw pattern to rate the equipment. NRCan is considering aligning with the UEF testing standard of the U.S. DOE by referencing CSA P.3-15. 

Product description

An instantaneous water heater heats water on demand as it flows for use in cooking, cleaning, and bathing, using natural gas or propane as the fuel source. Residential instantaneous water heaters have input rates of ≤250,000 Btu/h.

Energy performance testing standard

NRCan is considering referencing the following energy performance testing standard:

CSA P.3-15 - Testing method for measuring energy consumption and determining efficiencies of gas-fired and fuel oil-fired water heaters

The CSA testing standard can be ordered from:

CSA Group
Toll Free Phone: 1-800-463-6727
In Toronto, call 416-747-4044

Some CSA energy efficiency testing standards are also available at no cost on their website. To access free standards you will first need to create an account to join the CSA Communities of Interest.

Energy performance standard

Table 1. Proposed MEPS  for instantaneous water heaters with an input rate of ≤73.25 kW (≤250,000 Btu/h), with a storage tank of ≤7.6 L (2 US gal)
Maximum flow rate of product Draw pattern Minimum uniform energy factor (UEF)
0 L/min to <6.4 L/min
(0 to <1.7 gal/min)
Very small ≥0.86
6.4 L/min to <10.6 L/min
(1.7 to <2.8 gal/min)
Low ≥0.87
10.6 L/min to <15.1 L/min
(2.8 to < 4.0 gal/min)
Medium ≥0.87
≥15.1 L/min
(≥ 4.0 gal/min)
High ≥0.87

The proposed minimum UEF levels in Table 1 are intended to be a conversion into UEF of EF condensing levels for instantaneous water heaters. Using an EF rating, condensing instantaneous water heaters meet a 0.90 level or higher (ENERGY STAR® specifications). NRCan translated this condensing EF level to the UEF values shown in Table 1 using the following conversion equations and factors from the U.S. DOE Final Rule for the conversion of EF to UEF published on December 6, 2016.

In Section III. Part D.2.b) - Consumer Instantaneous Water Heaters, DOE published the formula:

UEF model equals n subscript r divided by 1 plus A multiplied by n subscript r

Where UEFmodel is an analytical model, nr is the recovery efficiency in decimal form; A is the coefficient for the analytical UEF conversion factor for consumer instantaneous water heaters (provided in Table III.7).

Using this equation and assuming a lower limit of 90% recovery efficiency for condensing models, NRCan determined the UEFmodel for each draw pattern in Table 2 below.  NRCan then used Table III.8- Consumer Instantaneous UEF Conversion Factor Equations, to convert the UEFmodel number to the UEF value.

Table 2. Conversion Calculations
Draw pattern Coefficient A – gas Recovery efficiency, nr UEFmodel UEF

Very small




















NRCan is considering MEPS level at the UEF value in Table 2 rounded to 2 significant digits, to be representative of a condensing instantaneous water heater.

Important dates

These regulations would come into force six months after the date of publication in the Canada Gazette, Part II.

NRCan proposes that the new standards would apply to instantaneous water heaters manufactured on or after January 1, 2020.

Labelling requirements

NRCan is not proposing a mandatory EnerGuide labelling requirement for instantaneous water heaters at this time.

Verification requirements

NRCan proposes that instantaneous water heaters carry a third party verification mark indicating that the product meets the MEPS and that information to be reported has been verified.

The verification mark is the mark of a Standards Council of Canada accredited certification body that operates an energy efficiency certification program for the product.

Reporting requirements

Energy efficiency report

The energy efficiency report required for instantaneous water heaters would include the following information:

  • name of product (i.e. instantaneous water heater)
  • brand name
  • model number
  • name of the manufacturer
  • name of the certification body whose verification mark would be affixed to the product
  • input rate, expressed in kW
  • uniform energy factor
  • volume of storage tank, in litres
  • maximum flow rate

The Regulations apply to products imported or shipped inter-provincially for sale or lease in Canada. This report must be submitted, by the dealer, to NRCan before the product is imported into Canada or traded inter-provincially for the first time.

Import report

A dealer who imports these products into Canada would include the following information on the customs release document:

  • name of product
  • model number
  • brand name
  • address of the dealer importing the product
  • purpose for which the product is being imported (i.e. for sale or lease in Canada without modification; for sale or lease in Canada after modification to comply with energy efficiency standards; or for use as a component in a product being exported from Canada)

Comments invited

The purpose of this bulletin is to provide stakeholders with technical detail required to comment on the requirements under consideration for instantaneous water heaters. 

Natural Resources Canada is specifically interested in receiving feedback on the condensing UEF values being proposed.

Additional information on Canada’s Energy Efficiency Regulations including a current list of Standards Council of Canada accredited certification bodies can be found in the Department’s website.

We welcome your comments by April 21, 2017. All correspondence should be forwarded to:

Natural Resources Canada
Office of Energy Efficiency
580 Booth Street
Ottawa, ON, K1A 0E4