loud buzzing is not "normal
usually indicates solenoid core not retracting to a "happy" position.
tap on it lightly when actuated, wee if it stops.
otherwise, unscrew it, rinse it out (be careful to not loose core or
little spring), re-install, check operation.
I had one that was all corroded (stainless bracket AND wires) hummed
like crazy, I replaced it with a new unit but I cleaned up the old,
soldered new leads & heat shriink tubing.
Works fine but I never put it back in service