I am a tennant in a council house. This is case where the permission for removing the radiator (and a wall) has been sought. One of the conditions for permission, that relates to the radiator, is that the gas safe registration number is obtained and the name of someone who does the work.
That condition is not enforceable with private housing, but looks as if it may with social housing.
The condition cannot relate to gas pipe work, because non is involved. Therefore, logic says,, it's likely to do with bringing the CH loop up to proper system pressure, after the work on the radiator is done. If someone "qualified" must bring the CH loop up to pressure, then, according to the condition, that workman must be a gas safe engineer.
It could be, (I don't know) that someone other than a gas safe engineer is sufficiently qualified to bring the CH loop up to pressure. Perhaps there are other people qualified. But, clearly, the council has explicitly stated it must be a gas safe engineer. Whether that makes any sense, others will know better. Does it make sense?
The issue then is one of qualification, with regard to setting up the system pressure. The council are obviously stipulating a qualification of the worker regarding that task, and they are stipulating a gas safety engineer.
Of course the condition hinders the DIYer who is trying to cut his costs. So, the DIYer asks is this condition necessary.