So when you do sign off an install what does that include? Boiler, flue and gas line. Does that also include any other pipework up to the boiler?
As far as Im aware there is no other ticket needed in a domestic property apart from Unvented Cylinders.
you have to put you flush the pipework .
what you used , temp on flow and return etc etc .
many things that we do as the norm .but we dont expect you to understand.
if it was that easy everybody would be doing it and there would be no need for RGI .