How to solve the problem of stopping hot water supply in hotels and residential apartments according to law?

Call the hotel front desk to solve it.

It depends on what kind of hot water it is, if it is hot water for washing face and bathing. Then you can call the front desk of the hotel and ask what caused the shortage of hot water. If the hotel can't normally supply hot water for people to wash their faces and bathe because of facility failure, they can check out and refund the room fee paid.

Find another hotel to stay in, the hotel belongs to its own reasons. Customers can't be forced to stay.