Common faults are: valve can not be reversed or reversing slow movement, gas leakage, solenoid pilot valve failure and so on.

(1) Check valves. Reversing valve can not be reversed or slow movement, generally due to poor lubrication, spring is stuck or damaged, oil or impurities stuck in the sliding part of the cause. In this respect, we should first check whether the oil mist is working properly and whether the viscosity of the lubricant is suitable. If necessary, replace the lubricating oil, clean the sliding part of the reversing valve, or replace the spring and reversing valve.

(2) Check valve. After a long time of use, the valve core seal ring wear, valve stem and seat damage phenomenon, resulting in valve gas leakage, valve movement slow or not normal reversing and other failures. At this point, should replace the seal ring, stem and seat, or the reversing valve to replace the new.

(3) If the solenoid pilot valve inlet, exhaust holes are sludge and other debris blocked, closed lax, active iron core is stuck, circuit failure, etc., can lead to reversing valve can not be normal. For the first 3 kinds of conditions should be cleaned pilot valve and active iron core of sludge and impurities. The circuit fault is divided into two kinds: control circuit fault and electromagnetic coil fault. Before checking the circuit fault, should first turn the reversing valve manual knob to rotate several, see the reversing valve under the rated pressure to be able to normal commutation, if can the normal commutation, then is the circuit to have the breakdown. When checking, the voltage of the solenoid coil can be measured to see if the rated voltage is reached, if the voltage is too low, the power supply in the control circuit and the associated stroke switch circuit should be further inspected. If the reversing valve in the rated voltage is not normal commutation, should check the electromagnetic coil connector (plug) is loose or contact is not real. Method is, unplug the plug, measure the resistance of the coil, if the resistance is too large or too small, indicating that the electromagnetic coil has been damaged, should be replaced.