https://www.youtube.com/watch?v=eE89B4zQoKc
Jeff, here is a youtube that shows the reset button. There is a power switch just inside the door of the girard unit. You can turn it off for 15 seconds and then turn it back on, but the reset button on the video is your best bet for getting hot water.
Also, turn your dial in the thrown room to a lower flame setting. Our setting is as low as it can be set.
It is quite possible that someone had the water on for an extended period of time and if the dial setting the flame is too high, the water will reach a pre-set limit and therefore shut down the heater.
Hope this helps,
Darrell