An acquaintance has had a new bathroom fitted, not by me. He asked me today about his bath/shower mixer tap, when he runs the bath taps the water is warm but when he pulls the lever for the shower the water is so boiling hot that he cant get under it. The tap has a TMV fitted set at 42deg I think he said, what I cant understand is how the water is boiling hot if it is going through the TMV. I told him to call back the plumber. Anyone have any thoughts on this?
