Core Viewpoint The China Consumers Association conducted a comparative test on 20 popular gas water heaters to provide consumers with objective and comprehensive product information, focusing on safety performance, energy efficiency, and constant temperature performance. Group 1: Sample Selection - The samples were purchased by the China Consumers Association staff as ordinary consumers, covering 15 brands with prices ranging from 2200 yuan to 7769.3 yuan [1] - The selected gas water heaters had CCC certification, energy efficiency levels of grade 2 or above, and a rated hot water output capacity between 13 kg/min and 16 kg/min [1] Group 2: Testing Projects - The testing focused on three core areas: safety performance, energy efficiency, and constant temperature performance, following national standards [5] - Key testing items included thermal efficiency, carbon monoxide (CO) content in flue gas, excessive wind pressure safety device, water temperature rise during water stoppage, minimum thermal load, cycle fluctuation, water temperature overshoot, and water temperature accuracy [6] Group 3: Main Conclusions - Thermal Efficiency: All samples met the claimed energy efficiency levels, with two models achieving grade 1 efficiency and the remaining 18 achieving grade 2 [7] - Carbon Monoxide Content: All samples met national standards, with some models showing CO levels below 0.01% [7] - Excessive Wind Pressure Safety Device: All samples met the national standard, with some models exceeding 700 Pa in wind pressure action value [7] - Water Temperature Rise: All samples demonstrated good temperature control, with four models showing a rise of no more than 0.5K [7][8] - Minimum Thermal Load: All samples met national standards, with some models showing a ratio of minimum thermal load to rated thermal load of less than 10% [8] - Cycle Fluctuation: Ten models showed temperature fluctuations of no more than 4°C under varying water flow conditions, indicating good constant temperature performance [9] - Water Temperature Overshoot: Eleven models maintained a temperature fluctuation of less than 2°C, reflecting good constant temperature performance [9] - Water Temperature Accuracy: All samples showed a deviation of water temperature within ±1°C under stable water flow conditions [9] Group 4: Performance Analysis - Thermal Efficiency: Higher thermal efficiency indicates better energy-saving performance, with two condensing gas water heaters achieving grade 1 efficiency [10][11] - Carbon Monoxide (CO) Content: All samples complied with the standard, with some models showing significantly lower CO levels [13][14] - Excessive Wind Pressure Safety Device: Most samples exceeded the required wind pressure action value, ensuring safety [15][16] - Water Temperature Rise: Most samples controlled the water temperature rise effectively, with several models showing exceptional performance [17]