Solenoid valve malfunction - the valve can not be closed

Solenoid valve can not be closed for two reasons: Physical obstacles, such as some gravel, dead leaves, to prevent the diaphragm is completely sealed, in the removal of these obstacles, you need to check the diaphragm and accessories for damage . Second: the pressure acting on the diaphragm is too small, there may be the following reasons: 1, the diaphragm chamber filter plugged. This will prevent water from entering the upper septum and will not generate enough water to close the septum. 2, the flow control handle is too high (maximum degree of opening). This low diaphragm / low pressure conditions, the diaphragm may hang high, but can not be sealed. 3, the valve seal between the upper and lower lax. Water is easily oozed out of it, which is not conducive to producing enough pressure to close the diaphragm. 4, the solenoid valve in the manual drain state. Commonly used (such as Nelson) solenoid valve has two kinds of manual operation (within the water, outside the water), outside the water is generally easy to identify, and within the water for the average customer is not easy to detect. 5, perforated diaphragm (only refers to the water flow valve). In the upper diaphragm chamber can not produce sufficient pressure to close the diaphragm. Carefully check, if necessary, replace the diaphragm. 6, solenoid valve installed in the wrong direction. The direction of the arrow on the solenoid valve is the flow direction.