Flexible assembly, combined with building in perfect. Solar collector composed of vacuum tubes, which is good in pressure bearing, high efficiency and sanitation. Tank can bear 2Mpa pressure. All the system with close circulation desgin. And with electric back up inside for no enough sun shine. Even if in cloudy or raining day, you can enjoy hot water. Separate pressurized solar water heater takes advantage of high absorptance and low emittance of vacuum tubes and converts absorbed radiation into heat energy and sends it rapidly to collector by heat pipe conductor. It can work efficiently in four seasons.