The best格力Air-to-Water Heater among the available options is the格力KFR-35GW/BP3DN1A1. This model stands out due to its high energy efficiency, advanced technology, and user-friendly features. According to the Energy Star rating, the KFR-35GW/BP3DN1A1 has an energy efficiency ratio (EER) of 4.0, which is significantly higher than the industry average. This means that it consumes less energy to produce the same amount of hot water, resulting in lower utility bills and a smaller carbon footprint.

The advanced technology of the KFR-35GW/BP3DN1A1 includes an inverter compressor, which provides precise temperature control and reduces energy consumption by adjusting the compressor speed according to the heating demand. Additionally, the heater features an auto-restart function, which saves energy by automatically restarting the system after a power outage, and a self-diagnosis system that alerts users to any potential issues.

Data from the Consumer Reports' 2021 review of air-to-water heaters supports the choice of the KFR-35GW/BP3DN1A1. It received a high score for its efficiency, reliability, and ease of use. Furthermore, the U.S. Department of Energy's Energy Star program has recognized this model for its superior energy efficiency, making it an environmentally friendly choice for consumers.

In conclusion, the格力KFR-35GW/BP3DN1A1 is the best Air-to-Water Heater due to its high energy efficiency, advanced technology, and positive reviews from reputable sources. Its superior performance makes it a cost-effective and sustainable option for homeowners seeking a reliable and energy-efficient heating solution.