Why Is Water Coming Out Of The Shower Head When Filling Bathtub

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It is common knowledge that plumbing pipes are interconnected behind the walls of your house. If you have a shower and tub that are connected, and the plumbing works correctly, only one should be used at a time. The shower or the tub – not both. 

However, if your shower head tends to leak when you turn on the faucet to your bathtub, there may be an underlying issue that needs to be fixed. Otherwise, you may end up spending more on your water bills and a loss of water pressure on your shower head.

In this blog post, we will look at the main causes for a shower head that leaks when a bathtub is filling up. Whether it’s a faulty diverter valve or a water pressure issue, we will also look at the best way to repair it and have your bathtub time back to being the blissful experience you are used to.

So let’s dive in and figure out what the issue is!

The Most Common Issues That Cause Shower Heads To Leak

Danco 10086 VersaSpray Portable Hand Held Shower Head Sprayer Fits Bathtubs Without Diverter, 1 Pack, White

The things which can cause the shower head to leak when filling your bathtub are basic plumbing issues, which are simple to fix. If you have more than a basic D.I.Y. knowledge, you can attempt most of these fixes, and if you do decide on calling out a plumber, you can at least diagnose the issue with the help of this article first.

The problem you are experiencing could be because of the following:

  • Faulty diverter valve
  • Piping installed incorrectly
  • Problem with the water flow

Asses What Is Causing The Problem With Your Bathtub

The first and most important step to resolving this issue is to find the problem. If you don’t know what’s the problem, how can you fix it, right?

As you are already experiencing leaking from your showerhead while the bathtub is filling, start by turning on your showerhead. If the faucet in your bathtub is leaking when the showerhead is on, it means that you have a diverter valve that may not be working correctly.

Replacing your leaky faucet should be a priority, as this water could leak behind your wall and create a much more serious issue.

Next, you should check the water pressure. If there is a difference, it may be because of a mistake during the installation process. Piping that is incorrectly installed can cause issues with water pressure in the system.

Water flow issues mean that you have no water from the faucet. 

These issues are very similar, but at this stage, we are trying to eliminate what the problem could be. You won’t know for sure until you dismantle it.

Now that we have an idea of what the potential issue can be, how do we repair it?

Inspect The Bathtub Faucet

Design House 522938 Slip-On Tub Diverter Spout, 5 Inch, Oil Rubbed Bronze

If your faucet and showerhead were functioning without an issue previously and this issue has recently developed, then the fault most probably lies with the bathtub faucet.

If the spout is the issue, you will not need to spend more time or money than necessary on this project. 

1. Removing the Faucet

There are two main types of faucets in bathtubs: slip-on and screw-on.
You will need the following tools:

2. Screwdriver or a Hex Key

Confirm what type of screws are on the underside of the faucets. Undo them using the correct tool.

3. Putty Knife/Razor blade

If you have a caulk, then use a razor blade or putty knife to remove the caulk in between the wall and the faucet. 

4. Large Pliers or Pipe Wrench

If it is difficult to unscrew or remove the faucet, then use some large pliers or a large pipe wrench to release it.

5. Flashlight or Phone light

Not completely necessary. However, the screw under the faucet may be difficult to see, the flashlight will help you find it.

The Process

  1. Locate the screws on your bathtub faucet and unscrew them off your faucet.
  1. Cut the caulk/silicone between the faucet and wall, if any.
  1. Remove the faucet from the wall. 

a. If the faucet is a screw-on, then place a rag over the faucet, and using large pliers or a pipe wrench, turn the faucet counterclockwise to unscrew it from the wall. 

b. If the faucet is a slide then either pull while strongly gripping the faucet or pull with a rag and pliers as in the process above to remove it from the wall.

To Replace or Not to Replace the Faucet Valve

Once the faucet has been removed, it’s easier to check where the issue lies. If no water flows out of the shower when you turn the water on, then the problem is most likely the bathtub spout which has a block or is old and needs to be replaced.

If you can see any debris, you can use a sharp object to dislodge it. If, however, you are unable to remove the dirt, it is best to replace the faucet with a new one to prevent any future issues.

The diverter valve could also be the reason for this leak. The diverter valve is responsible for routing the water to your shower head or the faucet, and if it’s not working properly, then it’s easier to just replace it with a new one.

How to Check for Installation Mishaps and Water Flow Issues, Causes, and Fixes

If your faucet seems to be working correctly, then it’s time to check for any installation issues which may be causing your problem.

Check the Following Measures Were Adhered to:

When installing plumbing pipes and hardware, the installer needs to follow certain rules. Check to make sure the installation follows the measures below:

Multiple Elbows Between the Valve Spout and the Port

There should be only one 90-degree angle in the pipe; additional ones will need to be removed as it can cause a lot of frustrating issues.

Bathtub Spout Valve Pipes should be 1/2″ Copper or 1/2” Galvanized Iron.

If you have any plastic piping, it needs to be replaced. It is unreliable and will deteriorate over time and lead to water pressure problems and blockages.

Check the Valve body is Facing the Correct Way Up

The valve body may have been installed upside down by mistake. This depends on whether it is a single handle or a double handle.

Single Handle – Ensure the valve body is not installed incorrectly. If the body is the wrong way up then reinstall by checking the valve, which will indicate the up position.

Double Handle – With a double-handle model, check the valve’s flow director. Reversing the direction will help the subject to where the water supplies are situated.

The valve and Bathtub Spout Distance is Within the Correct Tolerances

The distance between the tub spout and the valve needs to be 6 inches or higher and less than 11 inches. Even a small variation over or below the mentioned figures will result in problems.

Check for any Transitional Fittings.

Transitional pieces in the piping can cause problems and will need to be replaced.

Blockage in the Pipe

A restriction in the pipe is the most common reason for shower rise blocking a fluid flow of water to the faucet. Check the faucet for any blocked debris. Remove the faucet and insert an auger or a cable in the tub drop, loosening any build-up. Before you reattach the faucet, ensure the valve has been flushed.

Re-installing the Faucet

You either have a new faucet, or the old one has been cleaned and is ready to go in. Replacing any transitional pieces that you may have removed. Install the screw-on faucet by turning it clockwise and the slip-on faucet by pushing it into place and securing it against the wall. You will require pipe tape to help prevent any leaks from the faucet and to secure a tight seal.

Once the faucet is connected, apply caulk/silicone to it and let it dry. Wait a few hours, allowing the silicone to dry properly, and then turn the lever to allow the water to flow. You will have better water pressure, and your showerhead will not leak anymore.

My Water is Off, and My Showerhead Leaks, Why?

It might be distressing if your showerhead is leaking while the water is turned off. This is not a difficult problem to resolve. Start by checking your shower head for mineral build-up. Certain areas in the US have hard water, which causes lime and calcium buildup in the showerhead.

A clogged showerhead with mineral deposits prevents all the water in the shower from escaping during your shower. When you turn off the shower, this trapped water carries on dripping, making it appear as if you have a leak. This fix to this issue is very simple and easy.

The Fix

A few very simple ways to remedy this issue. All these items are readily available.

  • White vinegar
  • Lime-Away
  • CLR Remover (Calcium Lime Rust)

Fill a bag with white vinegar and tie it around the showerhead. Let the showerhead soak for an hour or two, and once the mineral deposits have been removed, wash the showerhead and re-attach it.

Alternatively, you can also use any recommended chemicals that are made specifically for this purpose, making sure to follow the instructions provided with the chemical cleaner.

Wrap up

In the article above, we explained what might be causing water to come out of the shower head when you’re filling your bathtub. Most of the resolutions are ones that can be attempted with simple tools and basic knowledge of D.I.Y. However, some of the issues require a little more expertise. 

If you are confident in your ability to resolve the issue, you can use the information provided to fix the problem. However, after reading, you realize this is too difficult a job. Then it is our advice to call a plumber, as dealing with water issues can often lead to bigger problems than the one you were trying to resolve. Good Luck.

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