Upstairs Bathroom Sink - Cold water tab runs very warm for first 30 seconds.
I do not know much about plumbing. I live in the USA. I have a 60 gallon gas water heater. My problem started maybe a month or two ago. In the bathroom sink of my home's second story the cold water in the sink will run very warm (almost hot) for the first 30 seconds. After that it goes back to cold water. All of my other stuff (shower, downstairs bathroom, kitchen sink) seems to be working fine - nothing abnormal. It is only that one sink in the upstairs bathroom. I have not changed anything before this problem started and I have not yet called a local plumber about the problem. Can anyone give me some advice or help?