The problem is in the basement bathroom. The water in the toilet just started to run all the time. As I was trying to adjust the water flow the socket holding the floater ball arm broke so I decided to upgrade the Tank Fill Valve. I had no problem doing this I’m only telling you about is because the hot water in the bathroom sink was working before I replaced the Tank Fill Valve and stopped work after. The water pipe, in the wall, that supplies water for the toilet is PVC and was in when we bought the house 15yrs ago. I think the former owner built this bathroom themselves, the work is sloppy. The toilet’s water doesn’t appear to be fasten to a stud, it wiggles. I didn’t pull on it or wiggle it too much as I was working on the toilet but I wiggle it a little. After I finished the toilet I went to wash my hands. The hot water flow was very weak. I checked the cut off valve under the sink turning the water off then on again, still a weak flow. I checked the cold water, it was working fine. I checked the other facets in the house and all the cold and hot water worked fine. There is a shower in this bathroom and from what I can tell both shower and sink are feed from the same water supply. I can’t hear any water running or dripping in the wall and nothing appears to be getting wet. The hot water heater isn’t even turning on and I can’t hear water flowing into it as I would expect if there was a major leak and I was losing hot water. I went back and checked the cut off value under the sink again; the water pipe feeding the sink wiggles to. I felt around as much as I could to see if there was I leak which there wasn’t. Now the hot water just drips out of the facet.

I suspect that you broke some junk loose and your hot water faucet valve or aerator is plugged with debris. Shut off the main. Remove the valve and inspect. Same for the aireator.