wacushing - Our 2002 211-S has the 6 gallon (DSI) heater and I suspect yours does too. The owners manual for the water heater states that the light will come on when you first switch it on and then go off. I believe it is only on while the igniter is attempting to light the gas. Be sure you have the bypass valves in proper alignment (under the sink) before you attempt lighting the heater electronically. In other words, you should have the water heater full of water. Mine blew a fuse the first time we used it - there was no water in the heater.
Gene
Trail-Lite 211-S w/5.7 Chevy