Water intrusion after Flushing water heater

On our 990, there was a 1/4" crack between the outside wall and the wing that was hidden by both front turnbuckle anchors. Didn't see it until I pulled the sink to get to something and could see light back behind the water heater.

But, I think you would have had to turn the water hose spraying straight up at the anchor to get that much water inside.

There has to be a crack in the tank seal around the drain or the trim ring.

Let us know what you find.

Is your trim ring well sealed against the pan with caulking? Otherwise when the anode rod is out and water pours out some of it will get between the pan and trim ring which seals the water heater to the exterior wall.

This is not normal or even remotely common.