Why is the pump stuck?

Possible fault sources:

a.When no oil is available inside the pump, pump core runs and causes dry friction, such that the pump core is heated up and glued (long-term operation without oil taking is not allowed)

b.Foreign substances occur inside the pump such that the pump core is stuck

Recommended solutions:

a.Shut down the dispenser immediately; wait till it is cool, reassemble the pump core, and replace it if it is already damaged

b.Disassemble and clean up the pump for recovery