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Why Your Tub Faucet Leaks When the Shower Is On

Posted On: September 26, 2022
Faucet

It’s the end of a long day, and you’re ready to take a hot, relaxing shower. You turn on your tub faucet to let the water heat. When it’s the right temperature, you switch it to your showerhead and hop in, but something’s not quite right.

You have less water pressure than usual. You fiddle with the showerhead and maybe even turn the shower on and off to try and fix it, but it doesn’t work. Then, you notice that the tub faucet leaks while the showerhead is on. The leaky tub faucet is pulling water pressure away from your showerhead.

While this is a common household problem, it is still an annoying issue that you should fix. A leaky tub faucet typically is caused by one of two issues: hard water buildup or a failed shower diverter valve.

Understanding why your tub faucet leaks when the shower is on is only step one. You also need to understand how to fix the problem so that you can restore water pressure for your showers.

Mineral Buildup from Hard Water

Hard water is when there is higher mineral content, usually calcium and magnesium, in the water. Over time, these dissolved minerals build up in your pipes and fixtures, causing less water to be able to pass through.

Your water is flowing through the valve at a certain rate. When it hits the mineral buildup and can’t get through, it finds a different path, resulting in your tub faucet leaking when your shower is on and less water pressure at the showerhead.

Alongside mineral buildup on your showerhead, other common signs of hard water include:

  • Feeling like there is a film on your hands after you wash them
  • Dull clothes or hair after you’ve washed them
  • Spots on your freshly-washed dishes
  • Calcium deposits on your shower walls
  • Dry and itchy skin

How to Remove Mineral Buildup

Many products are designed to remove hard water buildup from your kitchen and bathroom fixtures. However, many of these products are harsh and could hurt your plumbing.

Vinegar is a simple solution to hard water buildup that works because of its acidity. It can gently break down the minerals and help you wash them away, allowing the water to flow freely through the fixtures.

Here’s how you do it:

  • If you can remove the showerhead, unscrew it from its base and put it in a plastic bag. If not, fit the plastic bag around your showerhead and secure it with a rubber band.
  • Add enough white vinegar to cover the showerhead and mineral deposits.
  • Seal the bag and let the showerhead soak overnight or at least for several hours.
  • Reattach the showerhead if needed
  • Turn on your shower to test and see if your tub faucet still leaks.

If mineral buildup was the culprit, you should be back to showering with steady water pressure.

Failed Shower Diverter Valve

If removing hard water mineral buildup from your fixtures doesn’t help stop your tub faucet from leaking when the shower is on, you may have a failed shower diverter valve.

What is a Shower Diverter Valve?

The shower diverter valve is the mechanism that lets you change where your water flows. It controls if the water flows out of your tub faucet or showerhead. Typically, you can find shower diverter valves at the end of your tub spout.

When the shower diverter valve is open, the water flows directly through the tub faucet to fill your tub. Closing the valve diverts the water into your showerhead. When the diverter fails, not all the water goes into the showerhead, causing your tub faucet to leak when the shower is on.

Replacing your shower diverter is a project that is best left to a professional plumber.

Why Do Shower Diverter Valves Fail?

Shower diverters are simple mechanisms, but that doesn’t mean they don’t experience breakdowns. There are three common reasons shower diverters fail:

  • Broken seal from wear and tear
  • Corroded or cracked inner threads
  • Corroded or chipped finish or caulking

If you think you have a failed shower diverter valve, get your tub faucet repaired quickly by requesting professional plumbing repair.

Choose Genz-Ryan Heating, Cooling, Plumbing & Electrical for Your Plumbing Needs

Even minor plumbing problems can become unnecessary annoyances. The professional plumbers at Genz-Ryan Heating, Cooling, Plumbing & Electrical are ready to help you.

We’re a family-owned and -operated business dedicated to delivering exceptional service to our customers and helping our community. Our professionals are courteous and knowledgeable, providing superior workmanship and uncompromising customer satisfaction.

Call (612) 223-6158 or contact Genz-Ryan online today to request plumbing services in the Twin Cities.

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