The Xiaomi Home Assistant is a smart home system that integrates various devices, including water heaters. However, some users have reported an issue where the water heater always displays 'heating' in HomeKit, lacking the hvac_action status mapping. This article aims to provide a solution to this problem by implementing the hvac_action mapping logic in the water_heater platform. The expected behavior is to correctly map the water heater's status to the hvac_action, such as mapping '待机中' to 'off' or 'idle', and '用水中' or '预热中' to 'heating'. By fixing this issue, users can better control and monitor their water heaters using the Xiaomi Home Assistant. The problem was first reported on September 5, 2025, and the system logs showed no response. The Home Assistant Core version is 2025.9.0, and the Home Assistant Operation System version is 16.1. The Xiaomi Home Integration version is v0.4.2. To implement the hvac_action mapping logic, the water_heater platform needs to be updated to include the following mappings:待机中 → off / idle用水中、预热中 → heatingBy implementing these mappings, the Xiaomi Home Assistant can provide more accurate and reliable control over water heaters, enhancing the overall smart home experience.