In my area appliance connectors are allowed for water tanks. This one however basically bridges a gap between two rigid black steel pipes. I don’t like it, but is it wrong? Yes I am aware of the slew of other defects happening in this picture.
There should be a shut off valve at the rigid pipe supply line before the flexible connector.
There is. It is the red 1/4 turn valve.
In general, unless prohibited by AHJ, you can connect a water heater using a flexible appliance connector. However, you want to make sure the diameter of FAC used can serve the input BTUs of the water heater. Also the bending radius atop seems too tight, you cannot have right angle bends in FAC, and it appears too stretched out.
That was my original gripe with it but then I looked at how it went between rigid connections and thought about it more. If I saw it installed between rigid piping in a horizontal run I would call it out, so my conundrum was, “Is this any different?”
Depends how picky you want to get. You could argue it should be done like pictured here, but I don’t see it as a big deal unlike the other bunch of issues in your pic.
Thanks Simon. I just made a comment to have this reviewed by a plumber when they are repairing the flue, connections, TPR etc…