I attempted to inspect the anode rod on my water heater today. I pulled the plastic plug out and started picking away at the foam. I couldn't find the hex head screw I've read should be there on most water heaters. I stuck in a pair of long needle nose plyers 6" deep and felt no resistance. Anyone know what I'm doing wrong? It's an American Water Heater. The manual says "Remove and inspect the anode rod. Replace the anode rod if it is depleted." - Not very helpful. "