I was in the process of writing up the TPR drain line when I noticed an installation manual sitting next to the water heater. I always flip through these when I find them. Anyway, I noticed the manufacturer’s recommendation was that no more than FOUR elbows be installed in the line. As you can see, there are four in the pic, plus two more in the wall. There is no mention of this in the IRC that I could find.
Even a drain line installed properly to flow to gravity may have an excessive number of elbows, although I’ve never seen it. Just thought I’d pass this along.