Hi

I have installed a 7000 Btus Electrolux hi-wall mini split with the authorized services with a wall mount. When the compressor is on, it causes vibration on the wall which produces an annoying sound (seems like a ressonance sound). The wall mount has anti-vibration rubbers, but its not containing all the vibration.

What could be causing this? Maybe too much gas (it came with gas for 16 feet but the pipes are more or less 6 feet)? Ubalanced fan?

PS: I have contacted the authorized services, but they said it's normal, but i suspect they are lying or are just dumb.

Thank you.