the 16 year old regular type boiler (with hot tank in the airing cupboard, and mains feed i.e. no cold tank) in mydaughters top floor flat (3rd floor) is giving trouble, and the shower is very weak indeed. If I buy a new combi will the low shower pressure problems go away, or could it be a blockage to the shower as the pressure FEELS good in the kitchen (only by holding my hand over the taps!) please help, my daughter cant wash her long hair at home!! and I haven't got a clue about all this .The boiler was broke when she moved in , so I dont know how long the shower has been gutless.