Is the pump still working?
Yes- Uncouple the pipes from the unit and gauge test the unit directly at port. This ensures that the unit is producing a vacuum and there isn’t something as simple as a split pipe further inline where vacuum is being lost.
No – Is the pump free to turn by hand?
Yes – Check the electrical supply to the pump is uninterrupted. Check no overloads have been tripped or power disconnected in some way?
Test the motor with an electrical meter to ensure no phases are down and that the motor is actually working properly.
No – Has the pump seized?
Pumps can seize for a number of reason. If you cannot turn the pump by hand (turn it from the motor fan) this means the unit more than likely needs workshop attention.
Add: Tiantan Road,Huling Industrial Zones,Jiyuan ,Henan ,China