Cold water mystery in 1/2 bath
On Thanksgiving day, the cold water faucet in our 1/2 bath adjacent to our kitchen stopped producing water.
Some background: Our neighbor had his main shutoff valve replaced the day before Thanksgiving and that required our public water supply to be turned off at the street (we have a shared water connection). Our water was off for a few hours and, no surprise, there was some air in our lines after it was turned back on. I purged all of our faucets, shower, etc. throughout the house; everything worked fine. However, when I went to purge the cold water for our 1/2 bath, the faucet sputtered and then did not put out any water. The hot line is working fine.
I should mention that our house is more than 80 years old and a previous occupant had obvious work done over the years that was not always done properly, especially in regards to plumbing (which led to a flood in three rooms of our house last summer). The plumbing associated with our 1/2 bath is all CPVC, in contrast to the copper tubing throughout the rest of our house.
I already tried replacing the cartridge on the cold water side (although the former cartridge looked fine). Still no water. Could there be some kind of blockage due to material that was knocked loose during the noted work on my neighbor's shutoff? Is it time to replace the CPVC with copper?
I'm not sure what to do next; any advice would be appreciated.
-Daryl, learning how to keep up with an 80 year old house in PA