众所周知，太阳能热水器一般都安装在房屋顶或者小区楼顶，且水箱与集热管的连接非常紧密，水密度导致热水上浮、冷水下沉，保证了太阳能热水器本身的循环，因此基本不会出现水箱存水冷热水混合的情况。因此，可以确定这种情况是因为自来是水压的不稳定所造成的。

As we all know, solar water heaters are generally installed on the roof of houses or residential buildings, and the connection between water tank and heat collecting pipe is very close. The water density causes the hot water to float up and the cold water to sink, which ensures the circulation of the solar water heater itself. Therefore, there will be no mixing of water and hot water in the water tank. Therefore, it can be determined that this situation is due to the instability of water pressure.

                  

针对自来水水压不稳造成的洗澡忽冷忽热的情况，建议您采取如下方法避免：
It is suggested that you take the following measures to avoid the sudden cold and hot bath caused by the unstable water pressure of tap water:
1.避开用水高峰期，尽量选择小区用水低峰时间段来洗澡；
1. Avoid the peak period of water consumption, and try to choose the period of low peak water consumption to take a bath;
2.可以在屋顶（顶楼）太阳能热水器旁边同样高度加装冷水箱，用冷水箱的水调节太阳能用水，进行洗浴；
2. A cold water tank can be installed at the same height next to the solar water heater on the roof (top floor). The water from the cold water tank can be used to regulate the solar water for bathing;
3.在室内卫生间安装恒温阀，保证出水恒温等。
3. Install thermostatic valve in the indoor toilet to ensure the constant temperature of outlet water.