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CSA C656-14 (R2019): Energy Performance Requirements for Electric Storage Water Heaters
A technical overview of scope, key metrics, testing protocols, and compliance for Canadian residential and commercial water heaters
Scope
CSA C656-14 (R2019) is a Canadian standard that establishes minimum energy performance requirements and uniform test methods for electric storage water heaters. The standard applies to factory‑built, automatically controlled electric resistance water heaters with rated storage volumes from 50 L up to 760 L, intended for residential and some non‑residential applications. It covers both vertical and horizontal tank designs, single‑ and three‑phase configurations, and units equipped with either replaceable or non‑replaceable heating elements.
The primary objective of CSA C656‑14 is to set consistent efficiency benchmarks—such as energy factor (EF), recovery efficiency (RE), and standby loss (SL)—so that manufacturers, regulators, and consumers can compare products on a level playing field. It also defines the test conditions, instrumentation tolerances, and calculation methods needed to verify compliance. The 2019 reaffirmation confirms that the 2014 edition remains current without technical changes, but it may reference updated regulatory frameworks or adoption by provincial energy codes.
Standard Status: CSA C656‑14 (R2019) is a reaffirmed standard. It retains all technical content from the 2014 edition, ensuring continuity for manufacturers who have already qualified their products. No new requirements were introduced in the reaffirmation.
Technical Requirements
Key Performance Metrics
The standard defines three principal metrics that characterize an electric storage water heater's efficiency and capacity:
| Metric | Definition | Typical Test Conditions |
|---|---|---|
| First‑Hour Rating (FHR) | Volume of hot water (in litres) the heater can deliver in the first hour of use, starting with a fully heated tank. | Inlet temperature 14 °C, outlet 49 °C, ambient 20 °C. |
| Recovery Efficiency (RE) | Ratio of the heat added to the water to the electrical energy consumed during a recovery period (excluding standby losses). | Measured after a 6‑hour draw of 30 L/min; water temperature rise 35 °C. |
| Standby Loss (SL) | Rate of heat loss from the stored water while the unit is idle (W/m² or expressed as a percentage of input power). | Steady‑state conditions after 24 h; tank fully heated and no draws. |
Minimum Energy Factor (EF) Requirements
CSA C656‑14 prescribes minimum EF values that depend on the rated storage volume. The current tier (equivalent to U.S. Department of Energy 2015 levels for electric water heaters) is summarised below:
| Rated Volume (L) | Minimum Energy Factor (EF) |
|---|---|
| 50 – 180 | 0.93 – 0.95 |
| 181 – 270 | 0.92 |
| 271 – 380 | 0.90 |
| 381 – 480 | 0.88 |
| 481 – 760 | 0.86 |
Important: The EF values above reflect the current minimum. Manufacturers should verify any future amendments or provincial variations (e.g., Québec’s efficiency regulation may adopt a different floor).
Test Protocols and Instrumentation
All performance tests are performed at a controlled ambient temperature of 20 °C ± 2 °C, with an inlet water temperature of 14 °C ± 1 °C. The storage tank is set to a nominal outlet temperature of 49 °C (but other set points may be allowed for commercial units). Flow rates, draw patterns (e.g., the 6‑hour recovery test), and measurement tolerances are fully specified. Thermocouple placement, pressure taps, and data acquisition rates follow the guidelines of Annex A of the standard.
Design Note: To achieve the required EF values, manufacturers often increase foam insulation thickness (at least 50 mm of polyurethane is common), improve the tank's thermal break between inner tank and jacket, and use solid‑state thermostats that reduce cycling losses. Some designs incorporate dual heating elements to manage recovery without increasing standby loss.
Implementation Highlights
For product designers and quality engineers, implementing CSA C656‑14 involves three critical phases:
- Design for Efficiency: The standby loss requirement dictates the insulation package. A tank with a low surface‑area‑to‑volume ratio (e.g., short, wide cylinders) naturally loses less heat. The standard also affects the location and control of heating elements: lower elements should be positioned to minimise convection losses during idle periods.
- Simulation and Prototyping: Preliminary EF and FHR can be estimated using thermal network models before building prototypes. Once built, units must undergo the full test sequence in an accredited laboratory. The standard allows for a pre‑test screening at the manufacturer’s site, but certification data must come from a lab that participates in the Standards Council of Canada (SCC) program.
- Marking and Documentation: Each unit must carry a permanent nameplate showing the model number, rated volume, rated voltage and wattage, and the EF (or FHR) if claimed. The manufacturer's literature should reference CSA C656‑14 and, if applicable, the Canadian Energy Efficiency Regulations (SOR/94‑651) that adopt it.
Compliance Notes
CSA C656‑14 is referenced by provincial and territorial building codes and by the Energy Efficiency Regulations under Canada's Energy Efficiency Act. As of 2026, any electric storage water heater offered for sale in Canada must comply with the minimum EF values shown above unless exempted (e.g., for recreational vehicles, marine use, or very high‑capacity units above 760 L).
Certification bodies (e.g., CSA Group, UL, Intertek) perform the required testing and issue compliance reports. The manufacturer must ensure that the test sample is representative of production units. The standard also requires that the same model family share the same tank geometry, insulation, and heating element configuration; minor variations (such as element wattage) can be covered by a matrix test approach.
Caution: Non‑compliant water heaters may not be sold or leased in Canada. Fines under the Energy Efficiency Act can be significant. Additionally, some provinces (e.g., British Columbia, Québec) enforce their own labelling requirements that go beyond CSA C656‑14. Always verify local regulations before launching a product.
For imported units, the importer of record is responsible for ensuring compliance. Test reports from foreign laboratories can be accepted if the lab is accredited by an SCC‑recognized accreditation body and the test setup conforms to the identical conditions prescribed by CSA C656‑14.
Frequently Asked Questions
Q: What is the difference between CSA C656‑14 and the U.S. energy standard for water heaters?
A: The U.S. standard (10 CFR Part 430, Subpart B, Appendix E) is similar in metrics and test methodology, but Canada’s standby loss limits and EF tiers are adjusted for the colder inlet water temperatures (14 °C vs. 21 °C in the U.S.). As a result, a model meeting U.S. requirements may not automatically pass the Canadian standard without modifications.
A: The U.S. standard (10 CFR Part 430, Subpart B, Appendix E) is similar in metrics and test methodology, but Canada’s standby loss limits and EF tiers are adjusted for the colder inlet water temperatures (14 °C vs. 21 °C in the U.S.). As a result, a model meeting U.S. requirements may not automatically pass the Canadian standard without modifications.
Q: Are there any volumes or applications exempt from CSA C656‑14?
A: Yes. The standard exempts water heaters intended exclusively for recreational vehicles, marine vessels, or mobile homes if they are not connected to a permanent electrical supply. Also, units with a rated storage volume greater than 760 L or those designed for commercial/industrial use (e.g., steam generation) are outside the scope.
A: Yes. The standard exempts water heaters intended exclusively for recreational vehicles, marine vessels, or mobile homes if they are not connected to a permanent electrical supply. Also, units with a rated storage volume greater than 760 L or those designed for commercial/industrial use (e.g., steam generation) are outside the scope.
Q: How often must a product be re‑certified to CSA C656‑14?
A: There is no fixed recertification cycle. However, if the standard is revised or reaffirmed (as in 2019), the manufacturer should confirm that the existing test report still covers the current edition. Many certification bodies require a full test every 3–5 years to account for production changes.
A: There is no fixed recertification cycle. However, if the standard is revised or reaffirmed (as in 2019), the manufacturer should confirm that the existing test report still covers the current edition. Many certification bodies require a full test every 3–5 years to account for production changes.
Q: Can I use energy factor (EF) to compare gas and electric water heaters?
A: No. Electric water heaters typically have much higher EF values (0.86–0.95) than gas models (0.60–0.70) because the EF metric heavily penalizes combustion efficiency losses. For a fair comparison, use annual operating cost or the Uniform Energy Factor (UEF) if both products are rated under the same test procedure.
A: No. Electric water heaters typically have much higher EF values (0.86–0.95) than gas models (0.60–0.70) because the EF metric heavily penalizes combustion efficiency losses. For a fair comparison, use annual operating cost or the Uniform Energy Factor (UEF) if both products are rated under the same test procedure.
© 2026 – Technical overview of CSA C656‑14 (R2019). This article is for informational purposes and does not replace the official standard. Always refer to the latest edition of CSA C656‑14 for compliance.