pressure balance valve vs thermostatic valve

Pressure Balance Valve Vs Thermostatic Valve: Differences Explained

Last Updated on August 9, 2023

When it comes to choosing a valve for your plumbing system, there are two primary options to consider: pressure-balance valves and thermostatic valves. The distinction between these two types of valves lies in their ability to sense and control water temperature.

A pressure-balance valve senses and controls only the ratio of hot water to cold, which results in consistent water temperature, but limited control over the actual temperature. This type of valve works by maintaining a constant balance between the hot and cold water pressures, which can help to prevent scalding.

On the other hand, a thermostatic valve uses a thermometer or sensor to measure the actual water temperature and then adjusts the flow of hot and cold water accordingly to maintain a constant temperature. This provides precise temperature control for a more comfortable shower or bath experience, as well as protection against scalding.

In this discussion, let’s dive into the deep comparison of pressure-balance and thermostatic valves. Examine each type for its temperature control abilities, ease of operation, installation process and maintenance requirements to decide which will best suit your needs.

Temperature Control

One of the most important factors to consider when choosing between a pressure balancing valve and a thermostatic valve is temperature control. In a plumbing system, temperature control is essential for ensuring a comfortable shower or bath experience, as well as for preventing scalding.

Pressure balancing valves offer limited temperature control, as they work by maintaining a constant balance between hot and cold water pressures. This results in consistent water temperature, but users may find that the water temperature is not quite as warm or cool as they would like.

Pressure Balance Valve

On the other hand, thermostatic valves offer precise temperature control, as they use a thermometer or sensor to measure the water temperature and adjust the mix of hot and cold water to maintain a set temperature.

While pressure balancing valves may be sufficient for some households, those who are looking for greater control over their water temperature may prefer a thermostatic valve. However, it’s important to keep in mind that thermostatic valves tend to be more expensive and more complex than pressure balancing valves, so they may not be the best choice for everyone.


The operation of a pressure balancing valve and a thermostatic valve differs significantly, and this can have a major impact on the performance and effectiveness of the valve.

The pressure balancing valve adjusts the mix of hot and cold water based on changes in water pressure. They make sure the hot and cold water pressures are balanced, ensuring a consistent water temperature and protecting you from scalding.

Meanwhile, a thermostatic valve senses temperature changes and adjusts hot and cold water flow accordingly. Even when water pressure changes, this valve maintains a constant water temperature, so you can take a shower or bath in comfort.

In terms of operation, thermostatic valves are typically more complex than pressure balancing valves, as they require a thermometer or sensor to measure water temperature and adjust the flow of hot and cold water. This can make them more difficult to install and maintain and may also result in higher repair costs in the event of a malfunction.

However, the added complexity of a thermostatic valve also means that they are typically more precise and reliable than pressure balancing valves. This is especially important for households that require a consistent water temperature for a comfortable shower or bath experience, as well as for households with young children or elderly residents who are at a higher risk of scalding.

Adjusting Flow Rate

When it comes to adjusting the flow rate of hot and cold water, pressure balancing valves and thermostatic valves operate differently.

Pressure balancing valves use a diaphragm to sense changes in water pressure and adjust the mix of hot and cold water accordingly. This helps to maintain a consistent water temperature, but it may not always provide the precise flow rate control that you want.

For example, if you’re looking for a strong flow for a powerful shower or a weaker flow for a relaxing bath, a pressure balancing valve might not be able to provide that level of control.

 Thermostatic Valve

Alternatively, thermostatic valves detect temperature changes and adjust hot and cold water flow accordingly. The flow rate can be controlled precisely, which is great for people who like their showers or baths just right. Additionally, being able to control the flow rate can also help you conserve water.

However, it’s important to note that thermostatic valves can be more complex to install and maintain compared to pressure balancing valves. If the sensing element or thermometer malfunctions, it can result in an incorrect adjustment of the flow rate, which can be frustrating and costly to repair.

Cost Comparison

One of the key considerations when choosing between pressure balancing valves and thermostatic valves is cost.

Pressure balancing valves tend to be less expensive than thermostatic valves. This is because they are typically simpler in design and do not require a complex temperature sensing element. This makes them an attractive option for those who are working with a limited budget.

However, while thermostatic valves may have a higher upfront cost, they offer greater versatility and control over the flow rate and temperature of the water. They are also more likely to have features such as anti-scald protection, which can provide added safety for homeowners.

It’s worth noting that over time, the cost of ownership for a thermostatic valve may be lower due to its greater reliability and performance compared to a pressure balancing valve. Additionally, the added control and versatility provided by a thermostatic valve can lead to a more enjoyable showering or bathing experience.

Installation Comparison

Installation is important when choosing between pressure balancing valves and thermostatic valves.

Pressure balancing valves are known for their simple design, making them a great choice for DIY installations or for those working with a limited budget. Since they don’t require precise calibration, they can be installed with relative ease by someone with basic plumbing skills.

In contrast, thermostatic valves require a lot more precision and calibration. As a result, it’s recommended to leave the installation of a thermostatic valve to a professional plumber.

It’s important to note that the installation process for a thermostatic valve may take longer and require more work compared to a pressure balancing valve. This, combined with the additional components and precision needed during installation, can result in a higher cost for labor and materials.

Maintenance Comparison

There are some differences between balancing valves and thermostatic valves when it comes to maintaining them.

Pressure balancing valves are relatively low-maintenance and have few moving parts, making them a good choice for those who prefer simplicity. In most cases, they only require a periodic check of the valve’s operation to ensure it’s functioning correctly.

Thermostatic valves, on the other hand, require more regular maintenance due to their complex design and the number of moving parts involved. They need to be checked and calibrated on a regular basis to ensure accurate temperature control, which can be a more time-consuming and complex process compared to pressure balancing valves.

In addition, the wax-filled sensing element in a thermostatic valve can become clogged or damaged over time, which can affect the valve’s performance. In such cases, the valve may need to be replaced, which can be a more expensive repair compared to a pressure balancing valve.

Why do thermostatic valves fail?

The reasons why thermostatic valves can fail can vary, but some common causes include clogging, corrosion, and malfunction of internal components.

The valve may also fail due to improper installation or lack of maintenance, such as failure to replace worn-out seals or gaskets. Additionally, thermostatic valves can fail if they are exposed to extreme temperatures or sudden changes in temperature.

Can a thermostatic valve be repaired?

Yes, a thermostatic valve can be repaired. For example, if a thermostatic expansion valve (TXV) in an AC system fails, it can be repaired.

A damaged or broken shower cartridge can also be repaired, as it can cause issues such as dripping or running water, difficulty in turning handles, or not getting the intended water temperature. If a radiator valve becomes stuck, it can be fixed by removing the valve head, applying pressure, or tapping the valve.

Is a thermostatic valve necessary?

It depends on the specific application of the thermostatic valve.

For a shower system, a thermostatic valve is important as it helps to maintain a constant water temperature and control the amount of water flow. They are designed to do this by using a wax insert or a different thermosensitive element that expands or contracts to restrict the water supply once it reaches a certain heat threshold.

All new shower valves are required to have a pressure balancing mechanism built-in to prevent scalding, and a thermostatic valve is one of the two options for this mechanism.

For a central heating system, a thermostatic radiator valve is useful as it automatically maintains your preferred temperature setting by adjusting the heat output from the radiator.

However, as noted by one Reddit user, replacing an existing valve with a thermostatic one may not necessarily make sense for a central heating system as it still has to fill up the same amount, even if it restricts the flow of hot water.

What happens when the pressure control valve fails?

When a pressure balance valve fails, there can be several problems with the plumbing system in a home.

A pressure balance valve is designed to prevent water from becoming scalding hot in a shower, and if it fails, it can lead to temperature extremes, making it more difficult to take a shower. High water pressure can lead to leaks and burst pipes, and a pressure balance valve that fails could contribute to this issue.

Choose Between Pressure Balancing Vs Thermostatic Valve for Your Home’s Plumbing System

To sum it up, pressure balance valves are simpler and less complex than thermostatic ones but they offer less precision and reliability when it comes to controlling water temperature.

As opposed to thermostatic valves, which provide greater control but are harder to install or maintain. Cost-wise pressure balance is cheaper than thermostatic one; however, the decision between the two really depends on your personal preference as well as household requirements.

We hope that this blog post has given you enough information about these two types of valves to make an informed choice for your home.

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