Plumber did mentioned that he can install something for pressure but it can only be in the loft where water tank is so he said its not a good idea as i will have to go up there to change pressure. I'm sorry im so confused now with what i have and what it should be. All of you guys are amazing in writing all this details without even being there, it makes more worried that my guy been coming for 20 days now. He said today that he will maybe change the pump to UPS2 instead as its much more forgiving with old pipe system.The attic Tank may be your F&E tank for the boiler/system and you may have a unvented HW cylinder fed with mains cold water, if the hot water pressure/flow is the same as the cold water kitchen tap then probablay a unvented or look at the label on it, it should show the pressure.