5 Delta Shower Mixing Valve Problems (Plus How To Fix Them) | Mr. Kitchen Faucets (2024)

As a well-known household name, it’s no surprise that Delta products appear in thousands of homes nationwide. Lavatory faucets, bar faucets, toilets, bathtubs, showerheads, and more – the list goes on and on. Among its lengthy list of products, you’ll find shower mixing valves.

While these products are well-designed and perform well most of the time, issues arise every now and again. So, if your Delta shower mixing valve is on strike, here are a few common problems you might have (plus how to fix them).

How To Remove A Delta Shower Mixing Valve

For many of the following problems and solutions, you’ll need to remove the mixing valve from your Delta shower setup. To keep things organized, let’s review this process before evaluating the potential solutions to the problem.

The exact list of tools and materials you’ll need varies based on the shower model, but here are a few things you may need:

• Allen wrench
• Screwdriver
• Pliers
• Towel

Like any involved plumbing project, your first step is to turn off the water. So, start by turning off the water to the shower. In some cases, you might be able to turn off the water to the bathroom itself, but if you can’t, turn it off at the water main. Once you turn off the water, drain excess water from the lines by letting the shower run until it stops.

Once the water is off, you’ll need to remove the trim from around the shower valve. The exact process varies based on your particular model, so you can consult the documentation that came with the product for instructions specific to your model. If you don’t have them anymore, check online – you can usually find them in the “Supporting Documents” section of product listings. Alternatively, check Delta’s website.

Generally, the process is as simple as removing the plug button (if applicable) to expose the set screw. Once you remove the set screw, you can lift the handle away from the faucet body. Remove the escutcheon by loosening the set screw, then unthread the bonnet nut. This should expose the innards of the shower setup.

Now, you can start removing the mixing valve. If your model has a spacer, remove that with the sleeve. It should slide off of its place over the cartridge, body, and O-ring. Before you remove the valve cartridge assembly, take note of the position of the rotational limit on the cap. You’ll need to reinstall it the same way, so be sure you take note of this.

Next, remove the valve cartridge. Avoid prying the cartridge out of its place. Instead, reattach the handle to the stem, then rotate the stem approximately ¼ turn counterclockwise after the stop is contacted. Once you rotate it, remove the handle and lift the cartridge out of the faucet body.

5 Delta Shower Mixing Valve Problems (With Fixes)

Like any product, your Delta shower mixing valve may encounter issues after a while. Here are five common problems with correlating fixes.

1. Water Is Too Cold

If the water in your shower is too cold and won’t warm up, it might be the mixing valve to blame. This is usually the case when you notice cool water immediately after installing the new valve, as this problem doesn’t magically appear by itself.

So, if your water is too cold, start by checking the temperature limit. The exact mechanism varies based on your shower model, but the most common types are the push/pull and removable disc rotational stop limits.

Once you remove the trim to expose the mixing valve, adjust the temperature limit mechanism. If your shower has a removable disc, simply turn the disc counterclockwise to raise the temperature. Conversely, if your shower has a push/pull adjustment, gently pull the knob outward, then turn counterclockwise to raise the temperature.

Ensure you don’t raise the temperature too high, which could result in scalding. Make minor adjustments, then test the water’s temperature to see if it’s at an appropriate level.

2. Water Is Too Hot

Perhaps you have the opposite issue from the last – instead of your water being too cold, it’s far too hot. If this is the case, you might need to adjust the temperature limit in the opposite direction. Follow the same steps listed above, but instead of turning the limiter counterclockwise to raise the temperature, turn it clockwise to decrease the temperature.

Again, make the changes in small increments, testing the water after each adjustment. Once you reach a reasonable temperature limit, reassemble the faucet.

Note: Temperature issues may stem from your water heater. If your water is too hot or cold and adjusting the limiter doesn’t help, check the water heater. The problem will be widespread if the water heater is the culprit, so you can check other faucets throughout your home to confirm the problem.

3. Reversed Hot And Cold

If your Delta shower faucet provides cold water on the hot side and hot water on the cold side, the repair is pretty simple, providing the plumbing was installed correctly. Delta marks its valve cartridges with an “H” for hot and a “C” for cold, so you can quickly tell if the valve is backward. If the plumbing was installed backward, with the cold on the left and hot on the right, it’s a bit different.

To repair a reversed hot and cold Delta shower valve, simply remove the valve cartridge from the assembly by firmly pulling it toward you. Once you remove it from the assembly, rotate it 180 degrees so the hot is on the left and the cold is on the right.

Push the valve back into place, aligning the grooves, ensuring it’s firmly set in the faucet body. Once you’re done, reassemble the faucet and test it for proper function.

4. No Water Flow

Perhaps you just installed your new Delta shower valve, but once you turn on the water and test the faucet, no water comes out of the valve. When this happens, it can be the result of a flipped cartridge. If the cartridge is upside down in the assembly, it can prevent water flow or cause low water flow or varying temperatures.

First, confirm the valve is upside down by checking the lettering on the plastic cartridge rim. If the letters “UP” are upside down, the valve isn’t right-side up in the assembly. The process is very similar to the last repair – simply remove the valve cartridge from its place in the faucet body by firmly pulling it toward you.

Flip the cartridge so the letters “UP” face upward, ensuring the hot and cold sides are on the correct sides. Reinsert the cartridge into the faucet body, ensuring the grooves are aligned. Push firmly to seat the cartridge, then reassemble the faucet. Check your handiwork for proper function.

5. Low Water Flow

If everything appears okay with the valve itself and isn’t upside down, it may be overrun with mineral deposits. Over time, limescale can build up on the internal debris screen of these valves, causing low water flow issues. Of course, this shouldn’t be an issue if you have soft water in your home, but if you recently installed a water softener, the problem could have already existed before installing the softener.

So, you’ll need to clean the debris screen every now and again. To clean the screen, you’ll need to remove the brass cartridge body from the assembly. Use a crescent wrench, braced on the flats of the cartridge (grooves in the rounded portion of the cartridge), to remove the cartridge body.

Avoid bracing the cartridge on any point other than the length of the flats, as this could cause the plastic snaps to break, which renders the cartridge useless.

Then, position a second crescent wrench on the hex-shaped portion of the cartridge near the end of the cartridge body. Once the wrenches are in place, unscrew the front of the cartridge by turning the second wrench counterclockwise.

Once the cartridge is disassembled, carefully clean the debris screens by running them under warm water. Use an old, soft toothbrush to gently scrub hard-to-reach gunk. If the gunk won’t lift, soak the grubby portion of the cartridge in a 50/50 mix of water and white vinegar for several hours or overnight.

After soaking the cartridge, use a soft toothbrush to dislodge stubborn gunk, then rinse it clean with fresh water. Reassemble the cartridge, reinsert it in the assembly, then reassemble the faucet. Check your handiwork for proper function.

Note: Low flow issues can stem from other areas, including the shower head. So, if this remedy doesn’t work, try cleaning the shower head to remove built-up mineral deposits.

Frequently Asked Questions (FAQs)

How Do You Adjust A Delta Mixing Valve?

Adjusting a Delta mixing vale is reasonably straightforward, as they feature an easy-to-adjust temperature limiter. Once you remove the trim from the faucet, you can adjust the mixing valve to raise or lower the temperature based on the problem. Refer to problems one and two for a detailed guide on adjustments.

Can A Mixing Valve Get Clogged?

The valve cartridge can become blocked by mineral deposits, which is a common issue in homes with hard water. If you have hard water in your home, the minerals in the water may build up inside the valve after a while, eventually causing flow issues. In addition, these minerals can affect the flow from the showerhead, leading to problems stemming from there, as well.

Where Can I Find My Faucet’s Troubleshooting Instructions?

While Delta’s products come with an owner’s manual/installation guide/troubleshooting guide, many of us throw it away after installing the faucet. But if you don’t have it on hand when you need it, you might run into issues attempting to disassemble or troubleshoot your faucet.

Delta has multiple designs and models, so there are several sets of steps, each applicable to a different model. To find steps specific to your faucet, look up your faucet by name. Once you find a listing for your faucet (on Home Depot, Lowe’s, or Delta), scroll down to the “Documents & Specs” or “Supporting Documents” section.

In this section, you’ll find PDF links for product support, warranty information, maintenance guidance, and more. Click on the “Maintenance & Installation Sheet” document (or closest match). Browse through the guide to find steps specific to your faucet.

You can find instructions detailing how to install the faucet, so if you’re trying to disassemble the faucet, retrace the installation steps. In many cases, there’s troubleshooting information near the end of these sheets, so scroll all the way through to find the information you need.

You can always contact Delta’s customer support team for assistance if all else fails.