With the boilers I use, Powerflushing is reserved for restoring the system itself and then it has to be very bad to warrant the work.
For plate heat exchangered boilers it is more often than not a necessary part of installation and maintenance.
I would strongly advise one or more courses to teach you the ins and outs. Investing in a machine is perhaps something for further down the road - or if you know you are going to be doing one a month or something.