I have a hot water heater, about 2 years old, and I can get nothing but hot water from the second floor bathroom, shower and sink, cold faucets. The kitchen and bathroom on the first floor are fine. Any ideas on how this can be fixed?

Did this just start or has it been ongoing? Have you had a plumbing work done lately? Are the cold water supplies warm to the touch? Can you disconnect one and check? Back to you, Tom