Leveling the appliance prevents unnecessary noise and vibration. Check whether the appliance is perfectly level after installation.
If the appliance rocks when pushing the top plate of the appliance diagonally, adjust the feet again.
Timber or suspended type flooring may contribute to excessive vibration and unbalance. Re-enforcement or bracing of the timber floor may need to be considered to stop or reduce excessive noise and vibration.
Do not install the appliance on any elevated surface, stand or plinth as it can become unstable and fall causing serious injury and damage.