It should have level a surface---use a level on sides, side to side etc to see if the unit is out of level---most the feet are metal under the unit and can be turned up or down to level the machine.
We had one at home doing this and found if we pushed down on the front top the vibration went away, was supposed to be a temporary fix but put a can (pipe tobacco) with the plastic lids on both ends between it and the wall, worked so well the machine was quiet and level so its been there out of sight but working fine
Have someone level the unit with a long level and adjust the four feet as needed.
Answers & Comments
It should have level a surface---use a level on sides, side to side etc to see if the unit is out of level---most the feet are metal under the unit and can be turned up or down to level the machine.
We had one at home doing this and found if we pushed down on the front top the vibration went away, was supposed to be a temporary fix but put a can (pipe tobacco) with the plastic lids on both ends between it and the wall, worked so well the machine was quiet and level so its been there out of sight but working fine
Have someone level the unit with a long level and adjust the four feet as needed.