Hi all. Im just checking in regarding some plumbing work I got done last week. I don't want to mention the company but I wasn't too impressed with the guy.

Anyway we have a laundry room and wanted a recessed box behind the washing machine for the drain pipe thing.

He's done all the work but I have 2 concerns...
1. He's used a threaded S-drain thing below it and I'm about to close the gib up. What if it leaks? Is threaded piping allowed in a wall?

2. I had a sink s-drain changed by another plumber and he told me you need to have a air vent thing on the drain.
The one for the washing machine doesn't have a vent... should it?

Thank you for the help

Linkback: https://www.plumbers.nz/plumbing/1/washing-machine-drain-in-wall/2485/