My pump is noisy and pumps intermittently
Is the pump totally submerged. Pumps often become noisy if they are not totally submerged.
Is the noise being caused by the pump vibrating against the bowl? If so use some padding to dampen down the vibration.
If the noise has recently devleoped and the pump is pumping intermittently the rotor may have failed on your pump. To check the rotor remove it and hold the magnetic end in your hand, you should be able to rotate the top plastic part through most of a complete revolution but then it should catch and not turn. If you can rotate the top plastic part whilst holding the magnet still in your hand the rotor is faulty. Sometimes these are replaceable spares, check with your Henri dealer whether you can replace the rotor or if you need a new pump.