20 Most Recent Miele Cat & Dog 326i Bagged Canister Vacuum Questions & Answers

There's nothing you can do yourself when such an issue appears. Just faced the same situation and turned out that the devie just died.

I fix vacuums and the universal sign for a plugged up unit is the high-pitched sound. Someone will need to take the vacuum all apart and will find a plugged up hose down deep inside the machine somewhere. God bless your efforts.

First thing I would check are the motor brushes.

This unit comes with a silence setting in the system. As a result of your taking the unit apart you might have come in contact with this setting and tampered it. The silence setting combines the lowest noise output with the ideal power level for optimum cleaning results. This setting usually becomes activated when you switch the unit to energy saver mode.
Although with the 2200W of power which the motor boasts of if during your re-assembly you didnt cover the unit well this could have also brought about a discrepancy in the noise reduction method which the unit was assembled originally.
As you said there is no problem with your unit as it works excellently but the manner in which you re-assembled it has a space which allows the engine noise out and this is the problem why the unit has become so noisy.
Hope this support has been helpful?
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