Is this a drain? (above water softner loop)

[RobHydell]

I want to add a water softener and don't want to make assumptions. Is this a drain that I can use for the softener's backwash? Thanks in advance for the help.

The inlet and outlet at the bottom of the picture go to my whole house water filter.

[Winslow]

I want to add a water softener and don't want to make assumptions. Is this a drain that I can use for the softener's backwash? Thanks in advance for the help.

The inlet and outlet at the bottom of the picture go to my whole house water filter.

looks like a drain for a W/M standpipe.

[Brokersdad]

Think i'd take the end off of it and go to other areas of the house and run some water to see if you can hear it passing by the pipe to make sure it was in fact some type of drain. Who knows what people do when building

[kreemoweet]

You don't want to make assumptions ... so you get on the internet and ask folks who can't possibly know even as
much as you about that pipe, and ask THEM to make assumptions ... ?

[Gary Swart]

This place was plumbed by a handyman. All of that PVC pipe is a dead give away. So, there's no way to tell by looking. You may have to open the wall to figure it out.

[hj]

Pour some water into the pipe and see what happens. You have a catastrophe in the making with that PVC piping inside the house.

[Tom Sawyer]

But the guy at Home Depot said that it was the best stuff to use

[RobHydell]

looks like a drain for a W/M standpipe.

Thanks for the information.

[Terry]

You have a catastrophe in the making with that PVC piping inside the house.

PVC piping can't be used inside the home. That should be removed and replaced with CPVC or PEX
PVC is only rated for use underground where the temperatures can remain cooler and constant. Using PVC for domestic hot water is a real NO-NO.

[bluebinky]

Just guessing, but the pipe in question could also be a "cleanout".

[LLigetfa]

You don't want to make assumptions ... so you get on the internet and ask folks who can't possibly know even as
much as you about that pipe, and ask THEM to make assumptions ... ?

LOL... so true. I assume it is a combustion air supply.

[hj]

it could be, but the configuration is all wrong for a cleanout, especially since it does not appear to have a removable cap or plug. If it were a washing machine drain, then where are the hot and cold water supplies a WM would need.