Hi everyone.

This is a Kitchenaid KRFF507ESS about 4 years old now.

I noticed frost had built up on bottom of the drawer of the freezer.
Assumed this was a frozen evaporator drain so I took the freezer drawer off and got to the back of the freezer. There wasn't a lot of ice, but I defrosted it and it still wasn't draining.
Went around to the back and removed the p-trap drain pipe from the evaporator pain.

When I tried to flush it with water, it was obviously blocked.
Eventually all this rust 'sand' came out. I think this had settled in the p-trap.
The evaporator pan also was 'stained' with rust color.

I put it back together and its working again.

Two questions
a) Should i get a new p-trap as I imagine I haven't completely cleaned out the old one of rust debris
b) Where would this rust 'sand' come from -- is this a sign of a bigger problem or 'normal'

Thanks!
Mike