my condo unit had a working bathroom shower and sink for about a year but recently it has got cold water only during weekends and shortly after that plumber seen outside apparently taking care of this issue.
However after weekends, I noticed shower has gone completely hot and bathroom sink will almost instantly turns hot as soon as I turn the faucet on. I get some lukewarm water after slightly turn on the faucet from off position but there is no way to get a cold water from shower at all.
I suspected something might have messed up and contacted hoa but they were insisting shower cartridge is the problem. That old lady at hoa management has been messing a lot with other resident's issues including mine in terms of handling so I can not quite believe her word. Needless to say, I have been pissed off several times with them as they have been dropping a ball /flip flopping a lot, when handling the resident's issues but that is another thing.
Next thing as I am planning to ask the neighbours which seems to be the best way to isolate the problem. However I am wondering based on this, what is likely the problem. It is possible that the cartridge can be problematic but just the fact that both shower and sink setting just suddenly went completely off the chart right after plumbing job after months of working seemlessly is for me smoking gun.