New homeowner here. Temperature-pressure relief valve has been PVC plumbed to have a 1/4 turn valve (it's been closed this whole time) off a tee pointing down, then the other side of the tee sends the plumbing up to the joists, across the garage then down and out to drain/vent to the backyard. Is this safe?

I figure the quickest, easiest options are either to keep the valve open, or just rip the whole thing out. Appreciate any suggestions.