Loud humming noise when dishwasher is filling up with water

It is probably the seal on your dish washer door-- Bosch is know for being a quiet operating washer- try pushing on the door during the wash cycle and see if the humming quiets- If so- all you need to is replace the seal on your door-

your model is pretty new. just so you know your warrenty is 1 year parts and labor. 2 years on parts. it should not cost that much money.

there are two components that start before the circulation pump.(wash noise you hear)

first sounds you hear will be the drain pump. usually rattling noises if something is in it but it can make a hum noise if something is jamming the drain propeller up. which is accessible with a T20 torx driver. take the filters out and the mesh filter. and unscrew the screw in the base towards the left. pull out whatever is lodged.

the other humming sound can come from the next component that activates is the watervalve. make sure you dont have a kinked water intake line. otherwise its a bad valve. i have had to change a few of those water valves out already but not for a hum noise on your model. you have a new style water valve. when brands make new parts we get problems fast sometimes..