Do I need to install a non stop valve for the flush toilet?

It is best to install a check valve because the toilet tank is connected to the water main. Once the water is stopped, or when the water pressure is low, the water level drops rapidly, and there will be negative pressure in the water tank as a closed space, and the water inside is sucked into the main line, which mostly occurs in the user's home with more than 5 floors. A check valve can be installed on the line between the water meter and the toilet valve to prevent the water in the toilet from being sucked back.

The cost of the check valve is not high, about a few tens of yuan. If you really don't want to install it, the most primitive way is to close the water valve as soon as possible after the water is stopped to avoid the water in the tank being sucked back. Of course, these methods can only solve the problem of backflow of water in your own toilet tank, and it is best to put more water when the water supply is just restored, and put away the dirty water in the previous section.