How do the Stern contactless, basin touch, and shower touch kits differ
Kity Stern – contactless, touch-sensitive basin and touch-sensitive shower: how they differ and how to choose the right one
If you have ever looked for a replacement kit for a Stern faucet, you have probably come across three different designations – contactless kit, touch-sensitive basin kit and touch-sensitive shower kit. At first glance, this looks like an insignificant categorization, but in reality, these are three fundamentally different products that must not be confused with each other. The difference is not only in the name or design – it is different control principles, different electronics, different mechanical parts and in many cases also different mounting logic. If you buy the wrong kit, at best you will not be able to install it at all, and at worst you will install it, but the faucet will not work properly and you may damage other components.
In this article, we will examine all three types in depth – we will explain how they work technically, how they differ structurally and electronically, on which faucets they are used, what each kit contains and how to recognize which type you have at home. We will also add practical experience from installations and orders, where people most often make mistakes.
Basic principle: three different ways of controlling water
Before we go into details, it is necessary to understand what each type of kit actually solves. All three kits are essentially service kits for automatic or semi-automatic faucets – that is, faucets where you do not turn off the water with a classic rotating tap, but in some other way. This way of control defines which kit it is.
Contactless kit is intended for faucets that respond to the proximity of hands without any physical contact. A sensor (most often infrared) detects the presence of hands within range and opens the valve. When the hands are pulled away, the valve automatically closes. A person does not have to touch anything – not a key, not a button, not a sensor.
Touch-sensitive basin kit is intended for faucets where the valve is opened by touch – usually by touching the surface of the faucet or directly on the body of the faucet. A capacitive sensor recognizes the touch and opens or closes the water flow. It is therefore a touch on a stationary surface, not a mechanical pressing.
Touch-sensitive shower kit works on a similar principle to the basin type, but is structurally adapted to showers – different dimensions, different water protection, sometimes also different control logic (e.g. long touch to set temperature, short touch to turn on/off the flow). In addition, it must cope with different operating conditions than a basin faucet – higher flow, higher pressure, direct immersion.
Contactless kit – how it works and what it contains
Contactless faucets are among the most advanced fixtures that are installed not only in public spaces (hospitals, shopping centers, restaurants), but increasingly also in private bathrooms. The reason is simple – when washing hands, you do not have to touch anything that could be contaminated, and water consumption is lower, as water flows only when hands are under the tap.
The core of each contactless faucet is an infrared sensor – usually an active IR sensor that emits an infrared beam and measures the reflection. When a hand enters the detection area (usually a range of 10–20 cm), the reflection changes and the electronics evaluate it as a signal to open the valve. In most cases, the valve is an electronically controlled membrane valve (solenoid), which opens at a voltage of 6 V or 12 V from batteries or a transformer power supply.
A contactless kit for Stern faucets typically includes:
- Infrared sensor module with housing and cable
- Control board (PCB) with signal processing logic
- Electromagnetic valve (solenoid) with seals
- Battery box or adapter for a power supply
- Connecting cable between the sensor and the board
- Mounting accessories (screws, O-rings, sealing washers)
In practice, it happens that customers solve problems with contactless faucets and believe it is a fault of the entire kit, while the problem is only one component. Most often it is the sensor module – either the IR LED diode burns out or the lens in front of the sensor is clogged with limescale. In such cases, it is sufficient to replace the replacement infrared sensor for FREE or replacement infrared sensor for Classic – depending on which faucet model you have. It is not necessary to buy the entire kit if other parts (control board, valve) are working properly.
A typical problem with contactless faucets that I have repeatedly solved: the faucet starts to "catch" randomly – it lets water flow without reason, or on the contrary, does not react to the proximity of hands. In the first case, it is usually a problem with sensor sensitivity (setting the detection threshold) or a dirty lens. In the second case, it is either weak battery power or a faulty IR transmitter. We write more about these faults in the topic Common faults of contactless faucets and how to repair them with replacement parts in our Knowledge Center.
Touch faucet kit – capacitive sensor and its specifications
A touch faucet kit is designed for basins, where water flow is controlled by touching the surface of the faucet. It is not a mechanical button – no part is pressed, deflected, or fixed. It is a capacitive sensor built under the surface of the faucet, which reacts to the electrical capacitance of the human body. When you touch the special zone on the faucet, the capacitance slightly increases and the electronics recognizes this as a command to open or close the valve.
This solution has several interesting features, but also limitations. Unlike an IR sensor, it does not actively emit any radiation – it waits for a change in capacitance. The advantage is that it is not sensitive to reflections (e.g. shiny surface under the basin), the disadvantage is that the sensor may react to water droplets if they are in contact with the sensing area. Therefore, touch faucets must be structurally designed so that the sensing zone is not exposed to direct water splashing.
A touch faucet kit typically does not contain an IR sensor, but instead has:
- A capacitive sensor panel (often a thin-walled electrode built into the body of the faucet)
- A control board adapted for capacitive input signals
- An electromagnetic valve (of the same or similar type as in a non-touch kit)
- A power supply module
- Wiring and sealing elements
Important practical note: touch faucet kits are sensitive to water quality and the conductivity of the environment. In areas with soft water, sensors usually work reliably, but in areas with hard water, it may happen that limescale on the surface of the faucet changes the capacitance and the sensor starts to react unreliably – either not reacting at all or constantly. The solution is regular cleaning of the faucet surface and sensing zones. This fact is much less problematic in non-touch IR faucets, where limescale only affects the clarity of the lens.
Another difference: a touch faucet kit allows for so-called toggle logic – one touch turns the water on, another touch turns it off. Some models also have programmable time limits (e.g. automatic closure after 3 minutes as a protection against forgotten running water). This behavior is not common in IR faucets – they usually run only as long as the hands are in range.
Touch shower kit – where it differs from the faucet and why it matters
At first glance, a touch shower kit might seem like just a "larger" touch faucet kit. The opposite is true – it is a structurally significantly different product, designed for the specific conditions of a shower or bathtub. There are several differences at once.
Waterproofing and IP rating
A touch faucet is exposed to water splashing only occasionally – when washing hands, water flows down into the drain and the sensing area of the faucet is at a height where direct splashing usually does not occur. A shower faucet is in a completely different situation – it is exposed to direct water flow, steam, and high humidity during the entire shower. Therefore, a touch shower kit must have electronics with a higher degree of protection – at least IP65, in better versions IP67 (resistant to temporary submersion to a depth of 1 m for 30 minutes). A touch faucet typically has a protection rating of IP44 or IP54, which is simply insufficient for a shower.
Mechanical durability and construction
Shower faucets are exposed to greater mechanical vibrations (strong water flow, hose, shower head). The connectors of the sensor panel and connections on the control board must be better secured – otherwise, the connections gradually loosen and failures occur. A touch shower kit therefore has more robust mechanical connectors and usually also larger conductor cross-sections.
Control logic and response time
During showering, the comfort of control is more important than with a faucet. A faucet usually works on a simple principle: touch = ON, another touch = OFF, or ON after the touch duration. A shower faucet may have more complex logic:
- Short touch = start/stop of flow
- Long touch (e.g. 3 seconds) = entering temperature setting mode
- Double touch = switching between shower and bathtub spout
- LED indication of current water temperature
All of this is controlled by the PCB board inside the kit – and this is why the programming and firmware of the control board differ between faucet and shower kits, even though they could be physically mounted the same way. Using a faucet kit in a shower faucet would mean that the faucet would work, but the extended functions could not be used, or it would react differently than the user expects.
Flow rate and valve sizing
A shower faucet needs a higher flow rate than a faucet – during showering, the flow rate typically ranges from 8–15 l/min, while a faucet flow rate of 4–8 l/min is sufficient. The electromagnetic valve in a shower kit must be sized for a higher flow rate and have a larger seat diameter. If you were to use a faucet kit in a shower faucet, the valve would be too small and the shower head would not be able to maintain pressure – or the flow would be limited to an uncomfortable "trickle".
This is precisely why it is important to always follow compatibility with a specific faucet model when purchasing a replacement shower. For example, replacement shower for the Turin TRN11102 faucet is designed exactly for the parameters of this faucet, just like replacement shower for the Matera MTA11101 faucet – swapping for the wrong type can lead to poor flow or leakage. More about part compatibility can be found in the topic Compatibility of replacement parts: does a universal shower work in every faucet.
How to determine which type of kit you have at home – identification without documentation
This is a very common situation in practice: the sensor is installed, the documentation has been lost or was never provided, and you need to order the correct kit. Here is how to identify the type without any paperwork.
Step 1: Look for a sensor window or sensing panel
Look at the front or side of the sensor. If you see a small round or oval window (usually dark, plastic, 5–15 mm in diameter), it is almost certainly a contactless sensor with an IR sensor. This window is a lens through which the sensor emits and receives infrared light. If you do not see such a window, it may be a touch type.
Step 2: Look for a marked touch zone
Touch sensors usually have a visibly distinct zone – this may be a different color area, a hand or wave symbol, or simply a glossy surface on the body of the sensor. When you touch this zone, the sensor should respond. If this zone is in a suitable area for a basin (e.g., on the top of the faucet or on a side surface), it is a basin type. If the sensing area is located on a shower wall console or on a thermostatic valve, it is a shower type.
Step 3: Check the wiring and power supply
Contactless sensors always have a cable between the sensor module and the control board – usually a 2–4 conductor cable with a diameter of 3–5 mm. Touch sensors may have wiring hidden inside the body or the sensors are integrated directly into the valve without visible external cables. Also check the power supply: contactless sensors are usually powered by batteries (AA or alkaline 1.5 V) or via an external 230V/6V or 230V/12V adapter. Touch sensors may also have batteries, but sometimes they are powered directly from 230 V.
Step 4: Look for the model number on the sensor
Most professional valves have a model number engraved or painted on the body – usually on the bottom or in the area under the basin. The Stern marking usually consists of letters and numbers, where one letter indicates the series (e.g., FREE, CLASSIC) and the number indicates the version. With this marking, you can order the exact kit. For more information on sensor identification, see the topic Infrared sensor vs. touch control – what type of sensor do you have at home?
Most common mistakes when ordering a kit and how to avoid them
Over the years of practice, I repeatedly encounter the same mistakes. I will list them specifically so you can avoid them.
Mistake No. 1: The customer orders a contactless kit because "it sounds more modern." This has happened to us several times – the customer had an older touch sensor from Stern, ordered a contactless kit because they considered it to be "better." Result: the kit was not compatible with the mechanical body of the sensor, because the holes and mounting points for the IR sensor module were simply not prepared in the body of the sensor. The kit had to be returned.
Mistake No. 2: Confusing basin and shower kits by appearance. Both touch kits may look almost identical – the same control board, similar valve, similar connectors. The difference is in the IP rating and valve sizing, but that is not visible from a photo. The customer installed a basin kit in a shower sensor and after two months of intensive use, the electronics started to fail – reason: insufficient IP rating against steam and water during showering.
Mistake No. 3: Buying a complete kit instead of a single replacement part. If the problem is only with the sensor (not responding or responding inaccurately), there is no reason to buy the whole kit. It is enough to replace the specific component. For example, if you have the FREE series from Stern, the infrared sensor replacement for FREE is significantly cheaper and solves the problem just as effectively. Similarly, if you have the Classic series battery, the infrared sensor replacement for Classic is the right choice instead of a complete kit.
Mistake No. 4: Ignoring the power supply voltage. Some older Stern touchless batteries used 6V power supply, while newer models use 12V. If you replace the control board or solenoid with a newer type of kit with a different voltage, the valve will either react weakly (too low voltage) or may be damaged (too high voltage). Always check the power supply label on the original kit or in the documentation.
For the procedure of replacing the showerhead in a battery, see the topic How to replace a replacement showerhead in a battery yourself, and for replacing the infrared sensor, see Replacement of the infrared sensor in the battery – a step-by-step guide without calling a service technician.
Maintenance and extending the life of the kit
Kits – regardless of type – have their lifespan, but with proper maintenance, you can significantly extend it. This is especially true for electronic components in the bathroom, where humidity, limescale, and temperature fluctuations accelerate aging.
For a touchless kit, the most important thing is cleaning the IR lens. Limescale on the lens can significantly reduce the sensitivity of the sensor – it is enough to wipe the lens once a month with a soft cloth soaked in diluted vinegar. Also, regularly replace the batteries (if the power supply is battery-based) before they are completely drained – some control boards "freeze" when the voltage drops significantly and require a reset.
For touch kits, it is crucial to clean the sensing surface. If a layer of limescale forms on the touch zone, the capacitive sensor may lose sensitivity or react unpredictably. Use only cleaning agents suitable for faucets – avoid abrasive agents that could damage the surface layers.
For all types, regularly check the tightness at the valve connection point. Electromagnetic valves have rubber seals that harden with age and may start to leak. Usually, it is enough to replace only the O-ring, which is much cheaper than a new kit. If you are unsure about the dimensions, see the topic Diameter and thread of the head: how to determine the correct dimensions before ordering.
For shower kits, it is also important to check the mounting of the sensor panel on the wall or faucet – constant vibrations from the water flow can loosen the screws and the waterproof seal around the panel over time, which opens the way for moisture to reach the electronics.
In addition, we recommend paying attention to the selection of the appropriate replacement showerhead when replacing the shower accessories. For example, the replacement showerhead for the MZ-Expo MZE11106 battery is designed for a specific model – choosing the wrong diameter or thread can lead to leakage or reduced pressure.
Where are the price differences and is a more expensive kit always better?
The price of kits varies, and customers often ask about it. In general, a touchless kit is more expensive than a touch-based basin kit, and a touch-based shower kit is priced somewhere between or above the touchless one (due to higher IP protection and a larger valve).
A more expensive kit is not automatically better for your use – it is important that it fits your battery. If you have a touch-based basin battery, a touchless kit twice the price will not help you, because you cannot install it in that battery. On the contrary, if you have a touchless battery in public spaces with high usage frequency (office, store), an investment in a higher quality kit with a longer warranty will pay off in reliability and lower service costs.
What definitely saves money: do not order a complete kit if you can determine which specific component has failed. You can diagnose individual components (sensor, valve, board) yourself – we write in detail about this in the topic Common questions about replacement parts for bathroom batteries.
Frequently asked questions (FAQ)
Can I replace a touchless kit with a touch-based one if the touchless one suits me less?
Generally not – or at least very difficult. The body of the battery is structurally designed for a specific type of control. A touchless kit has an opening for the IR sensor module in a different position than the capacitive panel of a touch-based kit. Such a replacement would require mechanical interventions in the body of the faucet, which is not feasible in most cases without damaging the battery. An exception are some modular systems from Stern, where the manufacturer has prepared the body of the battery for both types – but this must be verified in the specific documentation.
How long does a typical Stern kit last with normal use?
With proper maintenance and normal usage frequency (private bathroom, about 10–30 activations per day), the realistic lifespan of the electronics is 5–8 years. The solenoid valve usually lasts longer – 8–12 years – if the water is sufficiently clean and filtered. In public spaces (hundreds of activations per day), the lifespan is reduced to 2–4 years for the electronics. The batteries in the power box should be replaced preventively every 6–12 months.
What to do if the kit does not respond immediately after installation?
The first thing: check the polarity of the power supply and the correctness of the connector wiring – even with simple connectors, it sometimes happens that the customer connects the cable backwards or to the wrong port. The second thing: check if the water supply is fully open – some kits require a certain minimum pressure (typically 0.5–1 bar) to properly open the solenoid. The third thing: with touchless kits, check if the IR lens is not covered by a protective film (this sometimes remains on the component during transport and is forgotten to be removed).
Is it possible to use a touch-based shower kit in a basin battery from the same manufacturer?
Technically, the physical connection may be compatible (same valve diameter, same connectors within one product family), but it is not recommended. Reasons: the shower kit is oversized for a higher flow rate, so with a basin flow rate, the valve will operate in a suboptimal range. In addition, the firmware of the control board is set for a different logic – you will have long touches and functions that make no sense at all for a basin. And the price will be higher without any benefit.
Why is my touchless battery letting water flow even without hands present?
This is a typical sign of either a dirty IR lens (reflection from a mirror or shiny surface nearby) or a faulty control board with a shifted sensitivity threshold. Try cleaning the lens first. If the problem persists, check if there is any reflective surface in the sensor's range (metal soap dish, polished mirror). Sometimes it is enough to simply slightly turn the battery or move nearby objects. If that does not help, it is likely necessary to replace the sensor module.
Do I need to call a professional to replace the kit, or can I do it myself?
It depends on your skills and the type of kit. Replacing the sensor module or control board in a touchless battery is usually quite simple – it involves disconnecting the connectors and replacing the part without interfering with the plumbing part. Replacing the solenoid requires closing the water supply and basic plumbing skills, but it is not an extremely complex task. The situation is similar with a shower kit, but you need to pay attention to proper waterproof sealing of the connections. In any case, we recommend studying the instructions provided with the kit before installation and possibly getting inspired by topics on DIY replacement in our Knowledge Center.
Conclusion: the right kit = the right diagnosis
The three types of Stern kits – touchless, touch-based basin, and touch-based shower – are three constructionally and electronically different products that are only connected by their uniform focus on comfort and hygiene in controlling water without a classic mechanical faucet. Their interchangeability is minimal and practically unrealistic without further interventions.
If you are unsure which type you have at home, proceed systematically: look for an IR lens (contactless), a touch zone marked on the faucet body (touch faucet), or a touch zone on the wall-mounted shower console (touch shower). If you find the model designation on the faucet, look for it in the manufacturer's documentation or simply write to us.
Before each order, verify not only the type of kit, but also the specific series (FREE, CLASSIC, etc.) – this determines the compatibility of the sensor module, the connector geometry, and the board firmware. Only in this way can you ensure that the new kit will actually work as intended.
Do you have a question about this topic?
Having trouble deciding or dealing with a specific situation in your home? Write to us – we are happy to help.