San Diego Plumbers › Plumbing Info › Plumbing Questions › Water Temperature Changes

Question: Why does the water temperature in the shower change when someone runs another outlet in the house?

Answer:

At the time of install, it is important to run pipes with enough volume and pressure so that many fixtures can be used at the same time. Running only two fixtures on a 1/2" line; so a standard bathroom would have a 3/4" line for cold until one fixture is taken off. A 1/2" line for the hot is fine. A nice follow guide now-adays is the plumbing code in many areas now. Get a pressure balanced tub and shower valve, which is a single handled valve that balances the hot and cold water to try to maintain a temperature range plus or minus 2 degrees.