hi boiler works fine. with all this cold weather we have had the c/heating on alot more. myson boiler with a potterton ep 2002 controller. we use the control manualy as we need heat and hot water etc. but today when i turned the heating off it didnt shut down the boiler, same with the hot water just a few mins ago. it did this last year then i bought a new 3 way thermostatic valve, that solved it. dont need to replace that allready do i ?