Its a new install and I know the tankless water heater that supplies that shower will get so hot you can't put your hand under it. However, in the shower, the handle goes all the way to the left and the water is hot, but not hot enough. Guests have complained and I think its a problem. The little white 'inner gear' has a 'tab' on it that is situated at 12 oclock. IS this the adjuster? If so, what's the process? Moen website and manual only tell me how to go COLDER from there...not what I need.