CSA B356-10 (2015): Safety and Performance Requirements for Portable Water Heaters

Scope of CSA B356-10 (2015)

CSA B356-10 (2015) applies to portable water heaters designed for temporary or periodic use, primarily in camping, tailgating, and other outdoor recreational activities. These appliances are intended to provide a convenient source of hot water for washing, dish cleaning, and showering in locations where permanent plumbing is unavailable.

This standard covers:

• Gas-fired portable water heaters that utilize propane, butane, or natural gas
• Heaters intended for outdoor use only — they must not be installed inside a building or in an enclosed space
• Heaters with nominal input ratings up to 24 kW (82,000 Btu/h)
• Heaters that may incorporate a shower head, faucet, or hose connection as part of the assembly

The standard does not apply to permanently installed water heaters, electric storage or instantaneous heaters, or equipment rated for commercial or industrial applications. It also excludes heaters that are part of a recreational vehicle (RV) or marine installation unless they are designed to be completely portable and not fixed to the vehicle structure.

Technical Requirements

General Construction and Safety Features

The standard mandates specific construction materials and design safety features to ensure reliability under challenging outdoor conditions. All heaters must be constructed of corrosion-resistant materials (e.g., stainless steel, anodized aluminum) and designed to withstand exposure to rain and wind. Critical safety devices include:

• Automatic gas shut-off valve – activates if the flame is extinguished or if an overheating condition is detected.
• Thermal relief device – prevents excessive pressure buildup; typically set to open at 400 kPa ± 50 kPa (58 ± 7 psi).
• Over-temperature cut-off (TCO) – interrupts gas supply if water temperature exceeds 85 °C.
• Stability and tipping protection – the heater must pass a 15° tilt test without spilling water or leaking gas.
• Rain shield or weatherproof enclosure – allows safe operation in light rain as defined by a 10-minute simulated rain test.

Gas Supply and Controls

Every heater must be equipped with a pressure regulator set to the appropriate output for the fuel, a manual shut‑off valve located upstream of the gas controls, and a thermocouple or thermopile flame failure device that shuts off gas within 20 seconds of flame loss. The gas connection must use a standard CGA 600 (for propane) or CGA 660 (for butane) fitting, and the entire gas train must be tested for leaks at 1.0 MPa (150 psi) for 2 minutes with no detectable pressure loss.

Table 1 summarizes the key performance criteria for gas pressure and flow rates as required by the standard.

Thermal Efficiency and Water Temperature Control

The standard requires a minimum power input sufficient to deliver a steady hot water flow of at least 1.5 L/min at a temperature rise of 45 °C above inlet. Additional performance limits include:

• Maximum water outlet temperature: 75 °C
• Thermostat accuracy: set point maintained within ± 5 °C
• Thermal efficiency: ≥ 70 % (ratio of heat transferred to water over heat consumed from gas)

Compliance is verified through a 15-minute continuous flow test at rated input, during which outlet temperature must remain stable within ± 2 °C after the first three minutes.

Implementation Highlights

Manufacturers incorporating CSA B356-10 (2015) into their product design should focus on the following elements during development:

1. Material selection – Use stainless steel for the heat exchanger, brass or aluminum alloy for gas fittings, and high‑temperature silicone seals that meet UL 94 V‑0 flammability rating.
2. Ignition system – Fit electronic spark ignition with a manual override; it must survive 50,000 consecutive ignitions without failure when tested under typical field conditions.
3. Venting and combustion air – Provide a combustion air inlet and flue outlet that prevent backflow and ingress of foreign objects. The flue terminal must include a 10 mm stainless steel mesh screen.
4. Marking and labeling – Every unit must be permanently marked with the model number, gas type, input rating (kW and Btu/h), date of manufacture (month/year), and a recognized certification mark (CSA, ULC, or equivalent).

Compliance Notes

Certification to CSA B356-10 (2015) is mandatory for portable water heaters sold in Canada, as the standard is referenced by provincial safety codes and enforced by authorities such as the Technical Standards and Safety Authority (TSSA) in Ontario and the Régie du bâtiment du Québec (RBQ).

Key steps to achieve compliance:

• Submit a representative sample to an accredited laboratory (e.g., CSA Group, Intertek, UL).
• Provide complete technical documentation including drawings, materials list, pressure ratings, and wiring/control diagrams.
• Successfully pass the full suite of tests: leak test, flame failure, thermal safety device operation, stability, water temperature stability, and rain exposure.
• Receive a certification report and license to affix the certification mark.

Ongoing compliance requires annual factory inspections. Any change to the construction, materials, or operating parameters must be reported and may require re‑testing.

Frequently Asked Questions

Last updated: 2026