If you are planning on installing a new shower in your home or replacing your old shower, then something that you are going to need to consider is what kind of valve you want that shower to have. Now, there are a few different types of shower valves out there, with two of the most popular and common ones being pressure balance and thermostatic shower valves.
What we want to do right now is to figure out what both of the two most popular ones are, how they work, and what makes them different from each other, as well as which one is the better one to get.
Pressure Balance and Thermostatic Shower Valves: The Basics
Before we start talking about the differences between pressure balanced shower valves and thermostatic shower valves, let’s first figure out what both of them actually are. Now, just in case you are wondering what a shower valve itself is, this is a special valve placed within a shower fixture that controls the flow, volume, and temperature of the water.
What Is a Pressure Balance Shower Valve?
First off, we have the pressure balance shower valve, which features just a single handle that controls both the temperature and volume of the water. This type of shower valve also has a dial that is the stopping point for the handle. This is what controls the hot to cold ratio. There is a spool or a piston that reacts to changes in water pressure, which helps to maintain the proper water ratio of hot to cold.
In other words, if you only move the handle a little bit, the device will allow all of the pressure or water to move through the cold water valve, if you move the handle to the halfway point there will be a 50/50 mix of hot and cold, and if you turn the handle all the way to the end, the valve will only let water or pressure come through the hot water tube.
There is a special mechanism on the inside that regulates and accounts for pressure. So, if you happen to be showering and somebody flushes the toilet, all of the cold water flows to the toilet instead of the shower, but the pressure balance valve will sense that there is reduced cold water pressure, and will therefore automatically reduce hot water pressure, therefore balancing the two out and preventing you from getting burned.
The pressure gets balanced when another fixture draws water, thus eliminating the problem of simultaneous showering and toilet flushing. Do keep in mind that if you have the handle turned to the maximum, it will allow the water to come out just as hot as it is heated to in your water heater.
What Is a Thermostatic Shower Valve?
OK, so whereas pressure balance shower valves react to changing water pressure, thermostatic shower valves react to temperature. A thermostatic shower valve actually has two handles, one that controls the temperature and one for the volume.
This way, you can control the flow of water and the temperature of it independently. What is also cool about this type of shower valve is if the water goes beyond the maximum temperature set, it will react on its own and send more cold water into the mix to regulate the temperature.
There is a small wax element located inside this valve that contracts or expands according to temperature. If the water were to exceed the highest set temperature, that wax component would expand to reduce the flow of hot water and to increase the flow of cold water. If the water is too cold, the wax element contracts to allow more hot water into the mix.
Now, if either the cold or hot water supplies fail, the valve will also close the other side off.
Pressure Balance vs. Thermostatic Shower Valves: What Are the Differences?
Now that we know what both pressure balance shower valves and thermostatic shower valves are, let’s figure out what the main differences between them are.
1. Fundamental Differences in Functionality
We aren’t going to spend too much time on this because of course we already discussed this above, but the fact of the matter is that these two types of shower valves do of course function in fundamentally different ways. One uses a piston or spool that senses water pressure and the other uses a temperature-sensitive wax element that contracts and expands (or electronics).
Pressure balance shower valves control your shower experience via pressure control, whereas thermostatic shower valves control your shower experience through temperature control.
2. Thermostatic Showers Have Precise Flow Control
When it comes to pressure balance shower valves, the issue is of course that there is only one handle that controls both the flow and the temperature of the water. This means that there is only really one flow rate. As soon as you turn the handle more than a little bit, you are at maximum flow.
On the other hand, with a thermostatic shower valve, because there are two handles, one for the volume and one for the temperature, you can accurately control just how much water you are letting out. This means that you can have just a little bit of water coming out or a lot, regardless of temperature, a benefit that you just don’t get with pressure balance valves.
3. Thermostatic Showers Have Precise Temperature Control
Closely related to the above point, because pressure balance shower valves only have the one handle, you also can’t independently control the temperature.
The bottom line is that with pressure balance shower valves, the flow and the temperature are linked together and cannot be changed independently. On the other hand, with a thermostatic shower valve you can control the temperature extremely precisely without having to change the water flow or volume.
4. Thermostatic Showers Have Temperature Memory
One of the biggest benefits that you get with trim thermostatic shower valves is the fact that they have temperature memory. Because there are two knobs, one for volume and one for temperature, when you turn the shower off, all you have to do is turn off the knob that controls the volume or water flow, all without having to change the knob that controls the temperature.
This means that the next time you get into the shower, you can just turn the water flow back on and the temperature will go back to the same level that you were at last time. In other words, with the pressure balance shower valve, you have to fiddle with the knobs to achieve the right temperature every single time.
5. Thermostatic Showers Can Help Save Water
Due to the fact that thermostatic shower valves allow you to control both the volume and the temperature of the water at the same time, they can also help to save water. For instance, if you are shaving in the shower and only need a very small amount of hot water coming out, you can do that. You can turn the water flow down and still keep the temperature up, thus providing you with a little bit of water.
This is unlike in pressure balance shower valves where you have to keep turning them on or off as you shave, or you just have to have them on full blast. Pressure balance shower valves in this way are definitely not very eco-friendly.
6. Thermostatic Showers Have Better Scald Protection
Now both of these shower valve types do help to prevent you from being scalded in the event that someone flushes the toilet.
However, with a thermostatic shower valve you can actually have your water heater set to the maximum possible temperature, thus preventing bacteria from forming in your water heater while only allowing a certain temperature to come out of the actual shower.
On the other hand, with a pressure balance shower valve, the water that comes out of the shower is the same temperature that it is in the water heater. The water comes out of the shower just as hot as it is in the water heater, and this can be a problem because it can lead to you being scalded.
7. Pressure Balance Showers Cost Less
For all of the benefits that thermostatic shower valves have over pressure balance shower valves, there is of course the fact that they are more expensive and in some cases much more expensive. Simply put, you get what you pay for and with thermostatic shower valves you get the best of the best.
Which of the Two Should You Get?
If you want something basic and you don’t want to spend much money, but you still want something that works well to prevent you from being scalded, then a pressure balance shower valve will do just fine.
However, if you want all of the benefits that come with being able to independently control the volume and the temperature of the water, then there is no better choice than a thermostatic shower valve.
Now that you know everything there is to know about both pressure balance and thermostatic shower valves, you can make an informed decision between the two and choose the one that works best for you.