I've bought brand a new house which uses 45kg LPG bottles, all the install has been done and I noticed there was a small 9kg bottle in the garage which they obviously used for testing the system. I've ordered 2 bottles to be delivered and have been told they won't connect the bottles and that I need to pay a gas fitter to connect the bottles the first time. Is this necessary? to get a gas fitter out just to screw in 2 bottles and turn them on? the whole system has been installed, checked and passed all its compliance certs so it seems a bit silly that I can't just connect the bottles myself..