My vaillant turbomax 342e system?

Ive got the powerflush system machine on and connected to my heating system. I accidently left the boiler on, but disconnected the machine from the radiator. Now my boiler does not work and makes weird noises and the temp shoots to 100 - 115' degrees and makes weird noises. I just turn the boiler off as soon as this happens. I want to know,

What has damaged on the boiler?
How much will it cost to get it all replaced?
From where can i get the parts
And also tips on cleaning out my system (UK resident) (London)
Cleaning scale from your radiators etc, whats the best way to do it. Thanks

Please call 07888670404 / 07965262257