The reason may be high pressure in the water heater, you can add some cool water to neutralize the solution; the reason may be just after heating the water, plumbing pipes and valves clogged, you can replace the inlet valve, unclogging clogged pipes to solve the problem; the reason may be that the water heater control switch is damaged, you can replace the control switch to solve the problem. 1, the water heater pressure, not easy on the water. If the water heater has just finished heating hot water, the internal temperature is high, the pressure is also high, so the water is difficult. You can first drain the hot water of the water heater, wait for a while and then turn on the water switch. 2, the water pipe is clogged. Check whether the water inlet pipe of the water heater is distorted, and whether there is any leakage in the connection port. If the water inlet pipe is twisted and clogged, you need to flatten the water pipe and clean the water inlet pipe of impurities, if the connection port has a leakage phenomenon, then the water heater pressure value is not enough, the water is difficult, so it is necessary to replenish the leakage point. 3, water heater water inlet control switch is damaged. Check whether the water inlet valve is closed, closed state can not be on the water. It may be that the valve's elastic clip is damaged and can not be opened automatically, you need to open the water inlet valve manually, and replace the valve. If the remaining hot water in the water heater can be discharged normally, then you can basically rule out the cause of damage to the water heater liner, only need to overhaul the water inlet system.