I thought you only turn the booster switch on when the water is not hot enough coming from your system (usually winter), so you turn it on for 30mins to an hour to get what you need, then turn it off again. Saves you money when NOT on....I have just installed a Rheem hot water system. Does anyone know whether the booster switch on the wall should be turned on at all times, ie., 24/7? Or it only needs to be turned on when you need the hot water? Thanks![]()