This is what the bypass values on the back on the water will look like for a three valve setup. Some setups only have two valves...
sample photos from google images
Notice the valves are oblong which can be used to tell you whether the valve is open or closed.
The middle valve in the first photo is probably turned wrong. It appears all three valves are OPEN in this photo
Some of the folks have reported they had to remove a panel to gain access to the rear of the water heater