I hope someone can help me with this. About a year ago we did a major remodeling of our upstairs including the master bathroom. We replaced the vanity. In the process of cutting some rotted flooring, the contractor cut into one of the water lines. He fixed it and it was fine. Just in the last couple of months, whenever we turn on the hot water only, there is a loud whining sound and the water flow is extremely low. Eventually the water flow increases and the whining noise stops. I know other posts have mentioned that if the piping has a lot of bends it may slow down the water flow and create the sound, but the repair the contractor made did not add any additional turns. In addition, the whining sound did not start right after the repairs were made.

Any thoughts would be appreciated!