Common Thermostatic Shower Problems & Fixes

Thermostatic showers are pretty freakin’ cool. They use a pre-set thermostat to control the temperatures your shower can reach. That means they prevent scalding or freezing temperatures. automatically regulating the temperature of your shower to ensure ideal conditions. While they’re really cool, there are also a few common thermostatic shower problems that you’ll likely need to address at some point. We’re going to walk through the most common ones and how to fix them in just a moment, so stay tuned.

The most common thermostatic shower problems are dirty valves, wonky water pressure, a reversed water supply, poorly installed or calibrated valves, poor water settings, or a dirty showerhead.

Let’s get right into it, because there are quite a few things that could go wrong, and we want them fixed now, right?

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Thermostatic Shower Problems & Fixes

We’re going to start with my personal favourite fix – cleaning. This is something that’s often overlooked by homeowners that really shouldn’t be. I know, I’m not your mother. But perhaps it’s time that you clean up in your bathroom. A common issue is that the showerhead or valves are dirty and need a good cleaning.

Dirty Showerhead

The first step with shower problems should pretty much always be cleaning your showerhead. A dirty showerhead can cause a number of issues and it’s easily resolved, so why not? Start with the following:

  • 1-2 litres of white distilled vinegar (enough to sumberge your showerhead)
  • 1-2 tbsp of baking soda
  • A bobby pin or paperclip
  • Stiff-bristled scrubby or toothbrush
  • A bowl big enough to hold your showerhead

Now – remove your showerhead. Submerge it in white vinegar and add a tablespoon of baking soda. Leave it to sit for at least 30 minutes while you look at other potential causes. Worst case, you didn’t need to do this and got some bonus cleaning done while troubleshooting.

Once the showerhead has sat for a bit, take it out and scrub with your scrubby or toothbrush. Use the paperclip or bobby pin to poke mineral or limescale buildup out of the holes in your showerhead. Keep scrubbing until it’s nice and clean, then reattach the showerhead to its proper place.

Read Next: Leaking bath waste and other issues.

Dirty Valves

This is very similar to the above process, so I recommend using the exact same approach and doing it at the same time. This will allow you to resolve multiple potential causes of the issue at once. Worst case, you don’t need to clean your showerhead or valves again for a while. Once again, you’ll need:

  1. 1 litre of distilled white vinegar
  2. .5-1 tbsp of baking soda (add more as needed, start small)
  3. Stiff bristled scrubby or toothbrush
  4. A bowl
  5. Screwdriver
  6. Channel lock pliers

Okay – now you need to turn off the water at the main (just trust me here). Remove the handle and trim for your shower faucet, exposing the valves in question. Remove the cartridge from the valve body with your pliers, along with any other valves that look like they’ve started to corrode or gather limescale.

Soak the valve(s) in white vinegar for an hour or so, adding a half tbsp of baking soda halfway through. Add more if needed, though you’ll likely only need a little bit. Remove the valve and rinse it thoroughly with cold water. Scrub any limescale or other buildup that you see.

While you’re soaking the valve(s), open the cold water side of your valve and run a gentle stream of cold water through. This will flush any residual grossness out. Be sure to have something ready to catch or redirect the water so you don’t make a mess. Once finished, replace the valve, retighten the temperature stop, and reattach the handle and trim.

Read Next: This is why your Triton shower has low pressure.

Wonky Water Supply & Valves

While you’re removing and cleaning your valves, it’s a good idea to inspect their installation. Depending on how well your shower was installed, it’s surprisingly common to find that they’ve been put in backwards.

This can lead to a number of issues, but you’re essentially looking to make sure everything matches up. The hot drain should lead to the hot valve, and cold to cold. If they’re installed improperly, flip them around and fix them once finished cleaning them off.

Water Pressure Issues

If your thermostatic shower is having water pressure issues, a common cause for this is the cartridge. Remove and inspect your cartridge (instructions to do so can be found here) to make sure nothing is dirty or jammed up. Take a look at your valves to ensure they’re not clogged or failing. If so, replace them (you should have cleaned them by now, so don’t worry about that).

Wrong Thermostat Settings (Water Too Hot/Cold)

This can be an issue with either your shower’s thermostat or the actual water heater itself. Start by checking the thermostatic valve to ensure it’s set properly. This can be done by simply removing the shower faucet handle and locating the thermostatic adjustment screw (which is usually clear as day to find). Adjust it by turning the screw and you should fix the issue. If not, move to your water heater.

The water heater can be adjusted in a number of ways, depending on its make and model. Find your owner’s manual and determine how to adjust its temperature settings. If the thermostatic valve wasn’t the source of the issue, it’s likely your water heater. Once you’ve checked both, you should have properly temped water.

If not, though, there’s two more things to check – your check valves and water lines. The check valves can be clogged (clean them out), or you could have had the water lines installed backwards (I know, surprising). The obvious fix to this is to install them properly (assuming this is the issue).

Final Thoughts

There’s a lot that can go wrong with a thermostatic shower. You always want to start by checking and cleaning your showerhead and valves, as they take the same process and are easy to access. Once that’s done, you can move on to checking your thermostat settings, water pressure, and water supply. Generally, a good cleaning of several involved parts will resolve any issues you may have, but not always. Worst case, you’ll need to replace a valve or two.

Should none of these steps solve the issue, it’s likely time to talk to a plumber. You can check that your water heater isn’t the source of the issue, but beyond that, it’ll be prudent to bring in a professional. They’ll be able to pinpoint the problem much faster than you, and you even checked a few things for them already! Now sit back, make a drink, and watch the professionals do what they do best.

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About the Author Dale Richardson

Love doing DIY and renovating my house. When I'm not doing that or working on this website, I love cooking, playing computer games and playing/watching football.