Thermostatic vs Pressure Balance Shower Valves Pros And Cons – Differences You Need To Know

Smartlydwelling is independent – we research, test, and rate the top products to help you make the right buying choice. We sometimes use affiliate links and may receive a small commission on your purchase. Learn more…

With consistent water temperature, thermostatic shower valves leave no room for surprises, while pressure balancing shower valves control the hot to cold water ratio. But there are a few other things you need to know...
Thermostatic vs Pressure Balance Shower Valves

Thermostatic vs pressure balance shower valves are quite the debate.

Now? We’ve simplified it for you!

But, most importantly, we’re long past those kinds of toilet pranks where a heartless soul would have flushed the toilet while you’re taking a shower just to get back at you.

Today…

…there are quite a number of pressure balance shower valves that you can install to protect yourself and your family, not just from those scalding pranks but from other bathroom accidents too.

Basically, these shower valves work in their own different ways to control and regulate your water pressure and, most importantly, temperature. There are the very basic and affordable ones, and then there are the pricey but very convenient and reliable valves.

The most common of them all is the thermostatic shower valve and the pressure balance shower valve.

It’s very easy to get confused between these two if you’re not very much a plumbing-savvy. 

But looking deeper into them…

…you’ll see that they’re very different from each other, from the way they function to the needs they answer to.

For starters, we’ve broken down the difference (and similarities) between thermostatic valves and pressure balance valves and how they can fit your and your family’s lifestyle.

Let’s dive in!

What Is a Pressure Balance Valve?

Pressure balance rough in valve

A water pressure balance shower valve is a standard shower mixing valve that controls the temperature of your shower water output by depending on and controlling the water pressure.

It’s the most basic shower valve type that you can get, and most houses (including old ones) usually come already installed with one.

Pressure balance valves are installed mainly for scald protection.

In case you haven’t realized by now…

…a sudden gush of scaldingly hot water while showering isn’t only uncomfortable and inconvenient but extremely hazardous, as well.

It can’t only burn your skin but can also shock the user and cause them to slip or fall onto the bathroom floors.

That’s also why pressure balance valves are now required in buildings and apartments in most cities. And if your home has an old one, you might also want to think about replacing them. You’d probably need the help of a professional plumber, though, but it’s always better safe than sorry!

Nevertheless…

…a pressure balance valve solves this problem by reducing the water output of one waterline whenever there’s a drop in temperature flow.

For example, you’re taking a nice warm shower when suddenly someone flushes the toilet or opens the sink faucet in the kitchen.

What happens next would be a drop in the pressure of your cold water line as half of it is now being redirected towards the sink or the toilet.

As a result…

…your shower water suddenly becomes hotter than it should be… in fact, it’s scaldingly hot!

Now, this is where the pressure balance shower valve comes in. 

It works in a way that it balances out the ratio of hot and cold water to deliver you the right temperature for your shower.

How does the valve do it?

It’s done by reducing the amount of hot water coming into your shower system so it could be equal to the cold water pressure. 

This could cause changes in the water temperature in your shower, such as delivering low-pressure water. But then, the temperature will remain the same cozy warmth that’s needed for your shower (or with around 3 degrees of difference)

In other words…

…a pressure balance valve maintains a constant (or near-constant) temperature without any regard to the water temperature.

It usually has a piston, diaphragm, spool, or the like that works that’s pressure-sensitive and can detect any drop in water pressure.

Pressure Balance Valve PROS

Pressure Balance Valve Pros

A pressure balance valve is considered the most basic valve that you can get for your shower. That being said, it comes with its good and bad. 

It does get the job done, but don’t expect it to have the extra bells and whistles.

So if you like to keep things simple…

…the simplicity of the pressure balance shower valve will delight you. It has only one handle that controls the temperature, so it’s easy to operate, that is if you don’t have a demanding need.

Because of this, pressure balance shower valves are suitable for people who live alone or couples with no children as you still need to be a bit careful with it.

But best of all…

…it’s also the most cost-effective choice as it’s easily one of the cheapest shower valve types on the market. So if you’re just starting out with your first major shower renovation or just looking for a good replacement, a pressure balance valve is a great option. 

Aside from that, it’s also undeniably durable when made with the right materials. Most pressure balance shower valves have a service life of around 50 years. 

Pressure Balance Valve CONS

Pressure Balance Valve Cons

Some people call the pressure balance valve a “primitive” shower valve. And no wonder, because it’s been around for many decades now. 

Aside from that, its pressure-sensitive spool is actually already being used as a bathroom contraption way, way back. 

So it’s no surprise that getting a pressure balance shower valve would come with some drawbacks. 

Naturally…

…you might have some issues with the pressure itself. The pressure balance shower valve doesn’t really work with temperature but with the water pressure in the shower

It works to keep the hot water and cold water balanced at all times, even at the cost of reducing one water line’s pressure just to get it equal with the other.

That’s why if you’re already a pressure balance valve user, you might notice that your pressure suddenly drops at times. Sure it’s a bit inconvenient, but it’s necessary, so your water temperature stays at the same safe and comfortable temperature.

But aside from this…

…because this kind of valve doesn’t rely on water temperature, if you set the valve at maximum temperature with the handle twisted all the way, you could very well have water output that is as hot as the water heater allows or even higher in some cases.

Of course, you can just turn the hotness down, but that still doesn’t solve the issue. 

As a matter of fact…

…it could do more harm than good, as setting your water heater to 140 degrees Fahrenheit is necessary to avoid microbial contamination. 

One example of this is the bacteria called Legionella that causes Legionnaire’s disease. This bacteria can actually survive at around 120 degrees Fahrenheit, so turning your heater down to this level could be harmful. 

That’s why it should always be set to around 140 degrees Fahrenheit, as bacteria can’t thrive in this temperature.

But then, that means you’d have to make do with the fluctuating pressure caused by the pressure balance valve. You could also get another fixture that takes care of the pressure issue.

Moreover…

…because of its rather very simple design, you can only have very few options for your shower. 

In case you didn’t know, a pressure balance valve doesn’t allow more than one function. In other words, you can’t use more than one showerhead at once.

Another common issue that users of pressure balance shower valves face is the rust and debris they collect over the years. These elements may force your valve to stick, resulting in even more loss of water pressure. 

And finally, as you’d most probably figured out by now, it won’t be convenient and easy to use for children, the elderly, and people with precision issues.

A pressure balance shower valve needs some adjustments at times, so it’s not very recommendable for the elders who live alone or in homes with small children. 

What Is a Thermostatic Shower Valve?

Thermostatic Shower Balancing System

An upgrade from the pressure balance valve, a thermostatic shower valve is also a type of shower mixing valve that regulates your shower water temperature.

But unlike the pressure balance valve…

…thermostatic shower valves are temperature-sensitive and don’t rely upon or affect the water pressure in order to achieve your pre-set temperature, which makes them fantastic to pair with a high pressure shower head.

That’s why I said “an upgrade.”

As a matter of fact, it uses an element within the unit that detects any changes in the temperature and adjusts it to your liking.

A common thermostatic shower valve element is wax. It expands and contracts depending on the water temperature and, in this way, controls the ratio of hot water and cold water in your shower.

Aside from this…

…thermostatic shower valves store water at high temperatures and mix it with cold water according to your needs.

You can also set your desired shower temperature in advance, and the thermostatic shower valve will remember it and make it the default temperature for your shower all the time.

The great thing about this is you don’t have to sacrifice your water pressure just to get the right temperature. With a thermostatic shower valve installed, you can have both!

Because of this…

…it’s deemed a safe option for families with children or the elderly. 

Being more advanced than the pressure balance valve, it has several components that you’d like to take note of:

Temperature control – in easier terms, these are the handles. A thermostatic shower valve commonly has two handles or temperature control. It’s also the component of the shower valve that’s visible to you.

Basically, a temperature control adjusts the water temperature instantly and to your liking. This is done by moving the handles that, in turn, move the piston that regulates the hot and cold water supply.

Element – it’s usually a wax element, but some models also use different materials. The element is very temperature-sensitive because it detects the slightest change in your water’s temperature and expands or contracts according to it.

Piston – Another important component is the piston. It works for hand in hand with the element and a spring, which is also another internal part of the thermostatic shower valve. 

A piston moves along the entryways for the cold water and hot water to regulate and balance them to the perfect ratio. This makes the piston a very important part of the valve and integral to maintaining a consistent temperature for your shower. 

These are just the main components that you’d want to take note of in order to take care of and maintain your thermostatic shower valve.

And what’s cooler?

Thermostatic valves react to a shortage of hot or cold water to avoid any inconveniences or harm to the user. Moreover, it instantly shuts down the supply of hot water when the cold water supply fails.

This is to protect the user from being scalded by pure hot water. And this is all done automatically, which makes it a very safe option for most families.

Thermostatic shower Valve PROS

Thermostatic Shower Valve Pros

As you might have already guessed, a thermostatic shower valve serves more than a few advantages. 

And what may be one of its best pros…

…is its capability to put you and your family to safety while using the shower. Because it can instantly react to very sudden changes in temperature, there’s no chance of anyone getting scalded ever again.

Should the supply of cold water pressure arriving at your shower run short because of someone using it in the room next door, the valve will automatically stop the water flow from the valve.

Yes, you’ve read that right!

You or your kids and the elderly don’t have to do anything anymore as you just have to set it and forget it, quite literally.

That being said…

…that makes it perfect for homes where the grannies stay or for families with children or disabled loved ones. You won’t have to worry about someone mishandling the shower and getting burned anymore.

To add to its user-friendliness, you won’t have to fiddle with different components to adjust the temperature or pressure anymore. All you’ll have to do is turn the handles according to your needs.

And that’s not all.

Not many people know it, but thermostatic valves help with your shower’s antimicrobial fight.

As mentioned earlier, bacteria can thrive in your heater if the temperature is around 120 to 100 degrees Fahrenheit or less.

Without a thermostatic shower valve, most people just opt to turn their heater temperature down, causing bacteria to breed.

But with a thermostatic valve installed, you can actually set your water heater to 140 degrees Fahrenheit to keep bacteria at bay and still have 100 degrees Fahrenheit water coming out of your shower head!

Furthermore…

…you can also adjust the flow of water while showering without affecting its temperature. 

In other words, you can turn the water off while you’re shampooing and still have the same temperature when you turn it back on. This is all thanks to the valve’s temperature-sensitive and fast-acting internal element. 

Blasting or trickling, the temperature of your shower water stays consistent and unaffected whatever you do!

Now, that’s not only very convenient but environmentally friendly, too, as you won’t have to keep your shower open just to maintain its temperature. 

What does that mean to you?

Well, that also means that it’s cost-efficient and could save you more money in the long run.

And best of all…

…you can definitely use it for more showerheads. So you can now enjoy showering with your fixed showerhead and handheld showerhead all at once!

Thermostatic Shower Valve CONS

Thermostatic Shower Valve Cons

Amazing as it may be, thermostatic shower valves have their drawbacks too, which is no surprise when we’re dealing with something so advanced and powerful.

Quite obviously…

…a thermostatic valve is much more expensive than its simpler counterpart, the pressure balance valve.

I, as a matter of fact, an average thermostatic valve usually costs about twice (or sometimes, even thrice) the price of a pressure balance valve. 

This is pretty understandable, though, as it has more components than the pressure balance valve.

But aside from the cost for the unit itself, you’d also want to prepare for the cost of installation.

Sure, more than one handle is great…

…but, that also means that it’s not as easy to install as the pressure-balancing valve.

If a beginner can easily learn how to install a pressure-balancing valve on the first try, a thermostatic valve might need professional help. This is especially true if you’re still a plumbing noob.

A thermostatic valve’s handles usually come with a plate behind it to cover the internal components, and it could prove to be a challenge to install.

Moreover, it’s double the challenge if you’re working with a small space. 

You’d most probably need to widen the opening on the wall or move some plumbing to accommodate a new (upgraded) shower valve.

And lastly…

…sure, we have lots of options on the market today, and they vary in materials and design. But it’s still common for thermostatic shower valves to have their internal components be made of materials that are susceptible to scale and mineral buildup.

It may not sound like a big deal now, but it can affect your shower valve’s performance over the years.

But it’s not the end of the world. You can always do regular maintenance, though that would be a bit of an inconvenience. 

Pressure Balance vs Thermostatic Shower Valves

Pressure Balance vs Thermostatic Shower Valves

If you’re still over the fence on what shower valve to get, below are comparisons by qualities for you so you can find what exactly fits your needs.

1. Temperature

Pressure balance valves and thermostatic shower valves have one goal when it comes to temperature: to keep it consistent and stable.

But they work in different ways.

A pressure-balancing valve works by sensing the changes in water pressure to balance the temperature. 

Whenever someone uses water in the other room, causing a drop of cold water in the shower, the pressure-balancing valve would then detect this drop and immediately reduce the flow of hot water to match the little that’s left of the cold water.

This way, you can still have the right water temperature, albeit with a drop in pressure.

With the thermostatic shower valve, you can have your desired shower temperature without compromising the pressure as it only mixes hot and cold water to the right ratio before delivering it to you. 

But aside from this…

…the two mostly differ when it comes to dealing with the water heater.

With thermostatic valves, you can set the temperature independently from the temperature of your water heater, so you can still put the heater on the maximum level without having scaldingly hot shower water.

2. Volume

Thermostatic Shower Valve With Volume Control

This is yet again where the two differ very noticeably.

With the pressure-balancing valve, temperature and pressure go hand in hand very closely. 

As a matter of fact…

…upon opening a pressure-balancing valve, you’ll first get a trickle of cool water. This is because the temperature increases with the pressure. 

So if you’re one for gentle and mild hot showers, this might not be the perfect choice for you.

Moreover, a pressure-balancing valve only has one handle, and it controls both temperature and pressure, so affecting the other is inevitable.

That being said, your shower water temperature depends on the water pressure of your hot and cold water. As a result, you may experience a drop of pressure every once in a while, but that’s necessary to achieve the right temperature that’s perfect for your shower.

On the flip side…

…a thermostatic valve has two handles. The first one is for controlling the temperature, and the other one is for the pressure and/or turning the water on and off.

This reflects how water temperature and pressure are independent of each other with the thermostatic shower valve.

Because of this…

…you can have the temperature you want in any pressure you prefer. May it be a gentle trickle or a powerful water blast, you can rest assured that your water temperature stays the same.

You can also just set your desired temperature on the other handle and leave it there permanently as you adjust just the volume every time you shower. 

And the cool thing about it?

It allows you to use more water outlets or showerheads at once! 

Yes, you’ve read that right.

Using a thermostatic shower valve lets you enjoy using your fixed showerhead and handheld showerhead all at the same time. 

3. Ease of use

Pressure Balance vs Thermostatic Shower Valves Pros and Cons

Pressure balance shower valves may be easier to install, but beyond that, thermostatic shower valves win hands down in the ease of use department.

How did that happen when pressure balance shower valves had one handle only?

Exactly. With just one handle, you’d have to turn the knob left and right repeatedly to be able to find the right temperature for showering. And you’ll have to do it every single day.

I’m pretty sure everyone knows that by now because we’ve used this valve once in our lives.

On the other hand, a thermostatic valve lets you set and forget your desired showering temperature because you have a separate handle for adjusting the pressure.

This way, you won’t have to find and set the right temperature every time you shower.

4. Price

Being the easier one to use with far more advanced features, the thermostatic valve is definitely way more expensive than the pressure-balancing valve.

So if you want utter comfort and convenience, you’ll definitely have to pay the price.

But if you just need something that will simply keep you from getting the hot water shock without the bells and whistles, then the more affordable pressure balance shower valves are for you. 

How can I choose the right Shower valve?

Modern Shower Valve And Trim Kit

Take this: you don’t have to choose the more expensive one all the time. What you need to do is observe your case and situation.

Do you live alone or with a partner and no one else? Perhaps, you’re still living with your parents or grannies.

Different living conditions require different shower valves as they must serve the exact needs of your household. The same goes for the condition of plumbing and water pressure in your residence.

If you’re living alone…

…or even if you’re just living with a partner, a pressure-balancing valve will certainly do. Quite obviously, if you’re both adults at home, you’d know how to adjust it to be able to achieve the right temperature with the right pressure without getting scalded.

But if you’re at home with children, the elderly, or the disabled, thermostatic shower valves are the ones for you.

Then, you wouldn’t have to be so anxious about letting the children use the shower as it will never get past the limit that you yourself had set. That alone makes it very worth it in its safety features. 

Aside from this…

…you’ll also want to take into account the trend of water pressure at home or in your area. If it’s usually frequented by uncontrollably high water pressure at random times, then a pressure-balancing valve may not work that well for you, and the thermostatic valve may be the better choice. 

Do I really need a thermostatic shower valve or a pressure balance shower valve?

Thermostatic Shower Valve Mixer Importance

Now, this is the question that most of us get over the years, and it’s usually from new homeowners.

Do I really need one of those pressure-balancing valves or thermostatic shower valves? Aren’t they just optional luxurious bathroom fixtures?

While, yes, it certainly adds a little more comfort and even luxury to your shower area, having a good shower mixing valve is necessary if you want to protect your family. 

And I’m not just talking about protecting from scalding or slipping on the floor.

As mentioned earlier, your water heater is actually some bacteria’s favorite home. This is all thanks to its oh-so-cozy and warm temperature.

So if you’re thinking of skipping the pressure-balancing valve or thermostatic valves in favor of just turning your heater’s temperature down, then think again.

With a thermostatic valve, you can set your heater to its maximum output temperature and then set the shower valve to a different, lower temperature, so it’s not too hot.

Also…

even using the pressure-balancing valve is better than just cranking your heater down. You can then get an anti-scalding fixture to accompany your mixing shower valve. 

Conclusion: Thermostatic vs Pressure Balance Valve 

Thermostatic Vs Pressure Balance Valve differences

For some people, the simpler, the better. For some, a more advanced and innovative approach is necessary.

Which one are you?

Just so you know, there’s no wrong choice if you’ve decided based on your home and family’s needs.

There’s nothing wrong with getting the more basic pressure-balancing valve if you really don’t need much help with your water pressure and temperature.

What matters…

…is you’re getting a shower valve at all!

It may appear as a luxury for some, but your shower area is your and your family’s comfort zone, and everyone- from the grannies to the grandkids- deserves a relaxing showering experience with zero fear of getting burned or slipping accidentally.