I have 20ft ceiling with exposed pipes.

I can hear the hot water tank's recirculating motor in my apartment. It's a loud hum. The pipe that the motor feeds from goes through my unit though oddly enough the noise is loudest down the pipe (in my unit), away from where it enters into my unit and away from the motor.

When it shuts off it sounds like a cat meowing, in need of help.

Maintenance has tried to grease the motor to eliminate the cat noise -no luck.

The main pipe coming through my unit is not completely sealed off at the ceiling (i.e. there's space between the pipe and the hole as it goes through the ceiling).

Is there anything that can be done (internal or external) to minimize the cat noise and the humming?

Is it normal to experience a lot of nose from these things? Meow sound included?

Thanks for any help.