Turn the hot water on , all the rads heat up,upstairs and downstairs, so no valves, I checked the cuboard, the 3/4 flow from the boiler goes into the cylinder . but before the cylinder it T´s off with 1/2in, which drops down to under the floor. The pump sits above the boiler in another room on the same floor. please can anyone advise me on the cheapest and fastest way without riping up floor boards to have a choice.