The lifespan of qualified products is 15 years. The reason is that as long as the bracket is well made, it will not rust or warp. If the water tank coating thickness is SUS304-2B or greater than 0.3, there will be no problem. The service life is mainly limited by the vacuum tube. Inert gases in the air can penetrate the glass, so a getter is placed in each vacuum tube to absorb inert gases entering the vacuum layer. But generally the amount put in can be used for 15 years. After 15 years, the vacuum degree will decrease more and more until it is no longer insulated, and the thermal efficiency will be very low. Good quality products can be used for 20 years, but thermal efficiency will decline more quickly after 15 years. As for small accessories, such as silicone rings, try to avoid the water temperature being too high whenuse of solar water heater. This way it will age more slowly. The way to prevent the water temperature from being too high is to use water frequently and refill it regularly.
The general design life is fifteen years, but this does not mean that it will be completely unusable after fifteen years. It's just that once the design life is reached, some components may need to be replaced or. repaired. Generally, over time, there will be corrosion and aging of the brackets, corrosion and leakage of the water tank, and scale of the vacuum tubes, etc., but they can all be solved.