You have decided on a mixer shower. Now comes another choice: manual or thermostatic?
Both use your home's hot and cold water supplies, but they control the temperature differently. That difference is particularly noticeable when somebody else turns on a tap, runs a washing machine or flushes a toilet while you are showering.
In this Allbits Shower Guide, we will explain how each type works, when the added temperature control is useful, and what else you need to check before choosing a valve or shower set. If you are still comparing the broader shower types, begin with our Complete Guide to Choosing a Shower.
The quick comparison
| Manual mixer shower | Thermostatic mixer shower | |
|---|---|---|
| How you set the temperature | Adjust the hot and cold mix with the controls | Select a temperature; the thermostatic valve adjusts the mix within its operating limits |
| Response to changing supplies | The temperature can change noticeably, depending on the system | Designed to reduce temperature fluctuations within the product's specified range |
| Temperature stop | Depends on the model; do not assume one is fitted | Many models have an adjustable or overrideable temperature stop; check the exact specification |
| Cold-supply failure protection | Do not assume automatic shut-off | Some thermostatic models include a thermal shut-off feature; verify the model and its instructions |
| Cost and complexity | Often a simpler valve arrangement | Thermostatic cartridge and additional temperature-control features |
| Water pressure | Needs a suitable supply for the chosen model | Also needs a suitable supply; thermostatic control does not boost pressure |
The table describes common designs, not a promise about every shower. Always check the particular product's technical information and have it installed and set up correctly.
What is a manual mixer shower?
A manual mixer combines hot and cold water according to the position of its handle or controls. You adjust it until the water feels comfortable. If supply conditions change, the balance of hot and cold water can change too, and you may need to readjust the shower.
Manual does not mean inferior or unsafe by definition. It can be a straightforward choice when the household's water supply is stable, the controls suit the users and the installation is specified correctly. But it does not provide the same automatic temperature response as a thermostatic valve.
At Allbits, examples include the Opal Manual Shower Valve with Diverter, which is listed with a 0.2 bar minimum operating pressure, and the Alaska Exposed Manual Shower Valve with Riser Rail, listed from 0.5 bar. Their designs and outlet arrangements are different, so check the whole kit as well as the valve. Browse manual showers.
What is a thermostatic mixer shower?
A thermostatic mixer also blends hot and cold water, but its valve senses changes in the incoming conditions and adjusts the mix to help maintain your selected temperature. That can make showering more comfortable when other taps are used in the home.
Many models use separate temperature and flow controls. Some have a temperature stop that requires a deliberate override to select a hotter setting. Other safety features, including how a model responds to a failed supply, vary by product. Read the manufacturer's instructions rather than assuming all thermostatic showers behave identically.
Allbits stocks a range of thermostatic shower sets and shower valves. For instance, the Aqualisa AQ150BAR2 combines a thermostatic bar mixer, fixed head, handset and a temperature override button. The Nostalgic Thermostatic Valve and Rigid Riser Kit offers a traditional look and is listed with a 0.2 bar minimum. Compatibility still depends on the actual water system.
What happens when someone turns on another tap?
Picture a morning in a busy household. You have set the shower to a comfortable temperature. Someone opens a tap elsewhere, changing the water available to the shower.
With a manual mixer, the mix set by your handle does not automatically respond in the same way as a thermostatic valve. Depending on the plumbing, you may feel the temperature change and need to adjust it.
With a thermostatic mixer, the valve is designed to compensate for changing inlet conditions and help hold the selected temperature, provided the supplies remain within its specified limits. It cannot compensate for every possible loss of water, and it cannot create hot water your boiler has stopped delivering.
That is why thermostatic control is often attractive in a shared or family bathroom. It gives you a more predictable shower when everyday water use around the home changes.
Is a thermostatic shower safer for a family bathroom?
It can offer useful protection against sudden temperature changes, especially when combined with a suitable temperature stop and correct installation. That may matter for children, older people and anyone who finds controls harder to adjust quickly.
But treat “thermostatic” as a feature to investigate, not a blanket guarantee. Check:
- The temperature-stop or override arrangement.
- The stated response to a failed hot or cold supply.
- The water pressures and temperature ranges the valve requires.
- Whether the installer can set and test the maximum outlet temperature appropriately.
- The needs of the people who will use the shower.
For a bathroom designed around a particular user's care or accessibility needs, ask a competent installer or specialist to specify a suitable product and assess the complete installation. An ordinary retail thermostatic mixer should not be assumed equivalent to a product specified for a care setting.
Does thermostatic mean better water pressure?
No. A thermostatic valve controls the water mix and temperature. A manual valve controls the mix according to its handle position. Neither label tells you how much water your system can deliver.
The valve, shower head and any diverter have their own operating requirements. The boiler or cylinder, incoming supply and pipework also affect performance. A shower that is rated for 0.2 bar and a shower column requiring 2.0 bar can both be thermostatic, but they suit very different supplies.
Read our Shower Water Pressure and Flow Explained , or ask your installer to check the running pressure and flow before ordering. A large head or several body jets will need particular attention regardless of the temperature control.
Which works with a combi, unvented or gravity-fed system?
Combi boiler: A compatible manual or thermostatic mixer can use the boiler's hot water and the cold mains. Check boiler hot-water output and what happens when another outlet runs. Thermostatic control helps manage temperature variations within its limits, but cannot increase boiler capacity.
Unvented cylinder: Either type can be considered if its pressure and flow requirements match the installation. Check the available hot water and simultaneous demand elsewhere in the home.
Gravity-fed cylinder and cold-water storage tank: Choose a model specified for the available lower-pressure supply, or discuss a correctly designed pumped system with an installer. Do not assume that every thermostatic valve needs high pressure or that every manual valve works at low pressure: the Allbits listings show requirements vary by model.
Not sure what system you have? Identify it before buying the shower. A good installer can check running hot and cold pressure and flow at the shower location, then compare those measurements with the manufacturer's instructions.
Exposed or concealed: does the control type affect the look?
You can find manual and thermostatic mixers in various visible or concealed formats. The control type and installation style are separate decisions.
An exposed bar or riser arrangement displays the valve on the finished wall and can suit some replacements. A concealed valve hides more of the working parts, leaving the controls and outlets visible. Concealed installation requires space behind the wall and a plan for future servicing.
A shower tower or column is another format: many Allbits Shower Towers & Columns incorporate thermostatic mixer controls and several outlets in one visible unit. Our Shower Towers and Columns Buying Guide explains the additional pressure, flow and layout checks.
What about electric showers?
Electric versus mixer describes where the shower gets its hot water. Manual versus thermostatic describes how its temperature is controlled. Some electric shower models have thermostatic control too, so these labels are not opposite categories.
If you are deciding between heating methods, our Electric vs Mixer Showers guide covers the supply, installation and performance differences.
Which should you choose?
Consider a thermostatic mixer if...
- Several people use water in the home at the same time.
- You value a shower temperature that needs less readjusting during everyday use.
- A temperature stop or another model-specific safety feature suits the users.
- You want a particular thermostatic set, valve or column and your supply supports it.
Consider a manual mixer if...
- You want a straightforward shower control and are comfortable adjusting it yourself.
- Your chosen model's layout, style and price suit the bathroom.
- The household's water supply and users make manual control appropriate.
- You have checked the model's operating requirements, rather than choosing solely on its lower price.
The best purchase is the model that works for your water system and your household. Once those are established, choose the controls and appearance you will enjoy using every day.
Common mistakes to avoid
- Assuming thermostatic control boosts pressure. It manages temperature, not water delivery.
- Assuming every thermostatic shower has the same safety features. Check the actual valve.
- Choosing a manual mixer only by price. Think about who uses it and how often other outlets run.
- Ignoring hot and cold supply requirements. Check running pressure and flow for both feeds.
- Confusing a temperature stop with a fixed temperature. Learn how the override operates and have the valve set up correctly.
- Assuming a two-head shower runs both heads together. Check the outlet controls and supply.
- Replacing a valve without checking connections. Pipe centres, inlet orientation and concealed access can differ.
The Allbits before-you-buy checklist
- Identify the home's water system and hot-water source.
- Have running hot and cold pressure and flow checked.
- Decide who will use the shower and what controls they find comfortable.
- Compare manual and thermostatic models that suit the actual supply.
- Check the temperature stop and any model-specific shut-off feature.
- Decide between exposed and concealed installation.
- Confirm the number of outlets and how they operate.
- Check head, handset and column requirements together with the valve.
- Ask an installer to review connections, setup and future servicing.
Frequently asked questions
What is the main difference between a thermostatic and manual shower?
A manual mixer follows the hot and cold mix set by its controls. A thermostatic mixer automatically adjusts the mix to help maintain the chosen temperature when incoming conditions change, within the product's operating limits.
Does a thermostatic shower stop scalding completely?
Do not assume any shower eliminates every risk. A suitable thermostatic valve and temperature stop can reduce the risk of sudden hot-water changes, but the actual features, supply conditions, installation and commissioning matter. Check the manufacturer's instructions and the needs of the users.
Can I fit a thermostatic shower to a low-pressure system?
Some models are designed for lower-pressure supplies. For example, the Allbits Nostalgic thermostatic kit is listed from 0.2 bar. Check both pressure and flow for the specific product and ask an installer to assess the complete system.
Is a manual shower the same as an electric shower?
No. A manual mixer uses the home's hot and cold water and lets you set their mix. A conventional electric shower heats incoming cold water inside its unit. Some electric models also have thermostatic temperature control.
Do thermostatic showers need electricity?
A conventional mechanical thermostatic mixer valve generally operates using the water supplies and does not need electricity for its temperature control. A digital shower, a pumped arrangement or a thermostatic electric shower has different electrical requirements. Check the exact model.
Can I swap a manual shower valve for a thermostatic one?
Possibly, but do not assume a direct fit. The new valve must suit the water system, pipe connections, mounting space and existing shower outlets. Ask an installer to inspect the installation before ordering.
Find the right controls for your bathroom
The real choice is how much temperature stability and control your household needs. A well-matched manual mixer can be simple and effective. A well-matched thermostatic mixer offers an extra layer of temperature regulation that many families value. In both cases, the water system and product specification come first.
Browse showers at Allbits, compare manual showers and shower valves, or contact Allbits with your current shower details.