Should be a single valve or a triple set of them right in front of or behind the water heater. I have never seen a bypass located in any other location other than right around the heater.
Barney
Single valve bypassTwo valve bypassThree valve bypass
2004 Sunnybrook Titan 30FKS TT
Hensley "Arrow" 1400# hitch (Sold)
Not towing now.
Former tow vehicles were 2016 Ram 2500 CTD, 2002 Ford F250, 7.3 PSD, 1997 Ram 2500 5.9 gas engine