My basement has a white pipe in the basement coming out of the concrete that is close to the wall. Is there a way to tell what this pipe is for without hiring a professional plumber? The PVC pipe is about 2-3 feet tall from the concrete floor. I like to know if it is a waste drainage pipe for future sink in the basement.

I recently installed a Grundfos recirculation pump to my water system. It works great with the exception of one bathroom where the tub/shower does not have flow. I have great flow and pressure at the sink and toilet in the same bathroom just not the tub/shower. I replaced the shower valve cartridge (pfister) but it seems like maybe the anti scald is closing not allowing the water through. If I remove the cartridge I have good flow and pressure coming out. I have the same pfister set up at the farthest bathroom and it works fine. This is an older system (20yrs old) maybe install a newer tub/shower valve system? I have switched out the cartridge with the one from the other bathroom and it does not work in this bathroom but they work in the farthest bathroom. The bathroom that is problematic is closet to the water heater. Everything worked fine prior to installation of Recircuation pump so i'm thinking the anti scald is too sensitive to the warmer water circulation in the cold side water lines? Any thoughts?