按照生产厂家的使用说明，经常更换过滤筒。Change the filter cartridge as often as instructed by the manufacturer.绝大多数锅炉有15至20年的使用期限。Most boilers have a lifespan of 15 to 20 years.所有产品均标有详尽的使用说明。All the products are labelled with comprehensive...