A friend of mine wants an old radiator in the kitchen removed and a new one installed but positioned on another wall. This means isolating the pipework for the old rad and t'ing off from another location in the house for the new one. First question, is there a recommended max distance from the t'ing off point to a rad? Looks like in this case it may be 4-5 metres depending on where it can be t'eed off from. Secondly, I'm only C&G6129 qualified but can proficiently install radiators (have done so in my own house). But, legally can I drain down a central heating system without having gas qualifications and being Gas Safe registered? Don't want the job if I'm not supposed to be doing it. CH system is powered by a combi boiler.