Hi Viperuk,
Powered splitters are a bit redundant these days and it's best not to use them with a modem.
At some point it has been required at the property. Either due to distance from the cabinet or the number of boxes in use at the house. Seen as you are using less boxes hopefully everything will be ok without the powered splitter.
Have you moved house with your old equipment on a quick start basis?
I would suggest having a tech install to make sure all open connections are closed off and the signal levels are verified to be within specification.
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I work for Virgin Media - but all opinions posted here are my own