If your water temperature is not regulating as it should be, then you may need to replace it, we have written a detailed guide on this here, as well as featuring a step by stem instructographic below.
All works carried out are from inside the shower and shouldn’t take more then 10-15 minutes to remove.
Don’t forget if you want further information, this guide will answer them here, once you removed the thermostatic cartridge from the valve housing, you will be able to identify it and compare to the the types we offer in our store here