Got a 2 year old shower pump
Grundfos / watermill PR50D - 1.5 Bar Regenerative Shower Pump
started making louder noises than usual a week ago but now just hums loudly but doesn't pump the water.
I suspected a blocked impeller so removed the pump and took the two side caps off and turned the impellers by hand. Re-fitted and still the same.
Should I have done more than just turning hand?
e.g. remove casing completely and check for obstructions.
Filters are clear.