Changing the Tee on copper central heating pipes?

Yes you can get copper push fit fittings (TECTIGHT) made by yorkshire fittings , 15mm and old 1/2" fittings same size, you will need 15mm tee`s and couplings will cost about �10.00. make sure that you cut pipes with pipe cutter and not hack saw ! you need smooth ends so has not to damage rubber seals. Used 100`s of these fittings never had any problems.