I have one of those gimmicky thermostatic mixing valve showers. It would either be overly hot or luke/cold, no in between. Got the replacement part from Riobel. Emailed Valentin and he booked me in 9am the next day. Came on time and muscled the mixing valve off to replace it. Showed me how the check stop and valve worked, as well mentioned that sentiment from the City supply eventually clogs these type of mixers. Overall, an easy experience.