First, I modified a solar water heater used at home according to the patented plan without infringing the patent rights
Second, Article 11 of the "Patent Law" stipulates that inventions and After a utility model patent right is granted, except as otherwise provided in this Law, no unit or individual may exploit the patent without the permission of the patentee, that is, it may not manufacture, use, offer for sale, sell, or import the utility model patent for production and business purposes. Its patented products, or the use of its patented methods and the use, offering to sell, selling, or importing products directly obtained according to the patented methods. Therefore, according to this regulation, if you modify a solar water heater used at home according to the patented plan, it is not for production and business purposes, but for your own use, so it does not infringe the patent rights.