Question about Suburban water heater w/ electric function.

If the weather is warm/hot I typically run mine on electric only. But if temps are cold (meaning the incoming water is cold) I run mine on both electric and propane for the better recovery rate. I never run propane only. I have forgotten to turn it off before going to bed and the propane WH kicking on at 2 am will wake you up. Electric will keep the tank hot enough the propane will not kick on until you start running the hot water.