Cold water in hot line in 1 of 4 bathroom faucets

[Mitch Schneider]

I hav a dilemma here. My master bathroom sink faucet runs cold water on both sides. If I turn the cold supply line off hot water returns. I replaced the kitchen single hole faucet today to a regular two controlled faucet. All bathrooms are dual controlled showers and sinks and all run hot and cold correctly. The half bath I just finished the remodel and it has a single hole faucet which is brand new. I tried turning the valves off to the washing machine and still have only cold water in the master bath sink. Not sure where the cross connection is occurring and what I should troubleshoot next. This has been occurring since we moved in August.

 

[nikono]

It's likely the brand new single hole faucet is where the problem is. But you may need only to adjust something.
In regard to faucet:
1. For faucet with handle.
"Some faucets have two small adjustment screws underneath the handle. The screw on the left controls hot water, while the screw on the right controls cold water. To increase water temperature, either turn the hot water screw counterclockwise or turn the cold water screw clockwise"
2. For shower.
"Slide the shower handle off the stem to expose the “Rotational Limit Stop” anti-scald valve. Grab the center of the “Rotational Limit Stop” and pull it toward you. Turn the Delta anti-scald valve to the left to increase the maximum temperature of the water, or turn it to the right to decrease the water temperature."