What Is GB 6932? China’s Standard for Domestic Gas Instantaneous Water Heaters

Status and Scope

• Current edition: GB 6932-2015, Domestic gas instantaneous water heaters (a revised edition has been under development; confirm the latest status before certification).
• Applies to: household gas instantaneous water heaters, including condensing types, using town gas; classified by installation location (indoor/outdoor), air-supply and flue-gas discharge, and by purpose (hot water only, heating only, or combined).
• Efficiency companion: GB 20665-2015 covers minimum efficiency and efficiency grades for gas instantaneous water heaters and gas-fired heating/combi boilers.

Classification by Air Supply and Flue Discharge

The exact model-prefix letters (for example the common forced-exhaust and outdoor designations) encode these categories; the standard’s classification clauses and the rating plate, rather than a product brochure, define the precise meaning.

The Key Tests

Efficiency: GB 20665

GB 20665-2015 sets the minimum allowable efficiency and the efficiency grades for gas instantaneous water heaters (including condensing heaters) and for gas-fired heating/combi boilers. The efficiency measurement itself uses the GB 6932 test method, so a heater is tested once and judged both for safety and for its grade. Condensing heaters, which recover latent heat, reach the higher grades; the grade label and minimum efficiency are checked together in market surveillance.

GB 6932 vs EN 26 vs North America

What This Means for an Exporter

1. Never ship or sell a flueless direct-discharge heater; it is banned in China and generally unacceptable elsewhere.
2. Do not treat GB 6932 compliance as CE or a North American listing — re-verify to EN 26 or the ANSI/CSA standard with the correct gas categories and pressures.
3. Match the air/flue type to the installation conditions of the destination country and keep the rating plate consistent.
4. Use one water-heater rig with GB/EN/ANSI profiles and segregate gas orifice and regulator settings by market.

Whether any additional Chinese market-access certification applies to a specific heater should be confirmed against the current catalogues of the State Administration for Market Regulation; build compliance on GB 6932 and GB 20665 and verify any extra requirement rather than assuming it.

One Rig, GB/EN/ANSI Profiles

Wanhe water heater test rigs (for example the WH-RS03 series, with water flow up to 30 L/min and 0.5% F.S. measurement) control water flow and inlet conditions, measure gas and water-side heat, thermal efficiency, temperature-rise/output, flue-gas CO and flame-failure performance, and store separate limit profiles. Selecting the GB, EN or ANSI profile switches the reference conditions and report format so the station prints a market-specific, serial-numbered report for the China file, the CE technical file or the North American listing.

How a Constant-Temperature Output Test Is Run

Two figures buyers care about — how much hot water a heater produces and how stable the temperature is — are measured under controlled, repeatable conditions rather than at a single tap. The rig sets and holds a defined inlet water temperature and flow, ignites the heater at the reference gas pressure, and records the outlet temperature as it settles. Hot-water output is expressed as the flow rate achievable at a specified temperature rise, while constant-temperature performance is checked by stepping the flow up and down (simulating a second tap opening) and recording the temperature overshoot, undershoot and recovery time. If inlet temperature, water pressure or gas pressure drift during the test, the same heater can appear to fail or pass for reasons unrelated to its design, which is why the rig regulates these inputs and logs them alongside the result. For condensing heaters the same run feeds the efficiency calculation. The station stores the curve, the recovery time and the pass/fail decision against the selected GB, EN or ANSI limits, keyed to the serial number, so a disputed field complaint can be compared directly with the factory record. Operators do not judge the result by watching the display; the rig applies the limits automatically, so two different shifts or two different factories reach the same decision for the same heater and cannot pass a unit by subjective judgement.

Common Mistakes

• Confusing a flued/balanced heater with the banned flueless direct-discharge type;
• Treating GB 6932 as equivalent to EN 26 CE compliance or a US listing;
• Looking for efficiency limits in GB 6932 instead of the separate GB 20665;
• Ignoring condensing versus non-condensing grade differences;
• Testing hot-water output without controlling inlet temperature and flow.