We have had a few cases of very loud clicking and banging noises coming from the coke apex machine.
Coke have said you should turn the machine off and check the syrup boxes are not getting low or near empty. you should replace them if they are. Also you could check the connections, as if they become to sticky they could block the pipes creating the problem. A hot wash in water for 5 mins will prevent the clogging of the pipes.
this should prevent any problems , however if it doesn't you can of course use freshdesk to tell us about the problem.
hope this helps.