Bath Controllers (USC1-117 and USC2-117) are designed for safe hot water use in the bathroom. Whenever turned on, the Bath Controller takes temperature-setting priority from the Main Controller.When first turned on, the Bath Controller returns to its previous setting – whatever you decide is appropriate for a comfortable bath, but never above 120 F (even if you have set the Main Controller for higher temperatures).And once hot water is running, you can raise the setting up to 112 F but no higher. If you really need higher temperatures in the bathroom, you need to close the tap and then change the setting. This way, temperatures can never be raised to higher, scalding temperatures while someone is in the shower.To return control to the Main Controller, simply turn the Bath Controller OFF. The Paloma Bath Controller is the key to the perfect shower every time. Teach your children to always turn on the Bath Controller for their shower, and it becomes the key to safe showering, too.