How often does the heated towel rack need to be changed?

The electric towel rack needs to be filled with water before starting to use, and it needs to be filled with tap water or purified water by itself.

The water injection is 95% of the total volume of the electric towel rack tube, and there is a 5% thermal expansion space.

Products with a power of 150W-600W can be injected into the position of the first horizontal pipe at the top.