Piston pumps occur in a vast number of different situations. Their occurrence ranges from fairly simple ones occurring in homes to regulate the flow of hot water to highly specialized and expensive valves for industries such as oil drilling.
Although there are numerous videos on YouTube showing people testing and replacing actuated valves in their own homes, it is vital that any work in a home involving electricity is done by a registered electrician who will be familiar with essential safety precautions and the fairly complex technical details that would be unknown to most people.
In an industrial setting in which there is very expensive machinery, the manufacturer's warranty is usually voided if testing and repairs are done in any way other than the prescribed procedure.
In simple home situations, the motor is tested with an ohmmeter to ensure the resistance is correct, and the micro switch is tested to ensure it performs correctly. If neither of these is the problem, then replacing the whole unit is not too great an expense.
In more complex situations, the actuator is disassembled as per manufacturer instructions after all safety steps have been taken. The following are often tested:
(ii) Free spinning and motion of moving parts in cases, cylinders and containers;
(iii) The existence of “scoring”;
(iv) Broken springs.
These steps are usually sufficient for the actuated valve.
A thorough inspection should occur of the rest of the process as a fault initially thought to come from the actuated valve may come from some other source.