Is your water heater trying to ignite when you switch it to gas? Are you getting a gas fault light on the control panel? Check the gas tube inside the hot water heater to make sure it isn't plugged with a spider nest or some other insect.
2013 Silverado 2500HD LTZ CC 6.6L Duramax Diesel
2014 Sunset Trail SF270BH
Holly & Buster, mini Dachshunds
2016: 1 trip, 3 nights in 1 state, 316 miles
2015: 5 trips, 18 nights in 3 states, 2707 miles
2014: 5 trips, 14 nights in 3 states, 2426 miles