First time motorhome buyer where is the water heater bypass?

My Holiday Rambler uses the 1 valve on the input design with a check valve on the output side. My check valve froze shut at the beginning of last season. All the water was working except for the hot. I just gutted the check valve and re-installed it. I always blow the lines out with compressed air, then dump the hot water tank. So I didn't need the bypass. I realize that may not be an option up north, but we've had some very cold winters in the Memphis area the last 2 years.