Keyrings.

[mark_airey]

i am if I'm authorised

but tell me why i shouldnt be??

Well because I'm assuming that you don't have a test kit to check there working? also if you remove a head on a gent sometimes all the addresses can jump one place meaning nothing is labeled up right.
Unfortunately big organisations seem to not like the idea of getting People in to do these things. Anyone can take a head down and replace it but wether it works and works properly is a different story!

(btw if you have had training on all of this, ignore me lol)

Unless its a conventional system and not an intelligent one....... and then as long as you replace the head properly there won't be any problem, clearly you should test it once installed to make sure that it is working correctly though