Installation of Bathtub Trap with Automatic or CLICK/CLACK System

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Installation of a Bathtub Drain with an Automatic or CLICK/CLACK System: A Complete Technical Guide

The bathtub drain is a part of the bathroom that most people never see – and that's precisely why it receives far less attention than it deserves. In fact, a poorly installed or improperly chosen bathtub drain is often the cause of most common drainage issues, odors, or slow drainage that bathroom complaints encounter most frequently. If you've ever struggled to choose between a traditional drain with a stopper and a modern automatic drain, or if you're facing an installation and don't know where to start – this article is exactly for you.

We'll cover everything: how an automatic drain and the CLICK/CLACK system work, how they differ, step-by-step installation, the most common mistakes and how to avoid them. We'll also include diagrams, real dimensions, and practical experience from the field.

What is a bathtub drain and why the type of closure matters

A bathtub drain performs two functions at once: it drains water from the tub into the sewer and at the same time prevents sewer odors from coming back through the drain. This "odor seal" is ensured by a water seal – usually a column of water that remains permanently in the curved pipe of the drain. If the water seal dries out (for example, due to long-term non-use of the bathroom) or the drain is improperly installed, odors penetrate into the bathroom. You can read more about this topic in the article Smelly drain or standing water: causes and solutions.

A key component of a bathtub drain is the drain closure mechanism – the mechanism by which you open or close the tub drain. Historically, it was a simple rubber stopper on a chain. Today, there are two modern solutions on the market that are more functional, convenient, and durable:

Automatic drain (automat) – closure controlled by a lever rod on the overflow cover
CLICK/CLACK drain – closure controlled by pressing directly on the drain itself with the foot

Both systems are functionally equivalent, but they differ in the way of control, installation requirements, and suitability for different types of tubs.

Automatic bathtub drain: how it works and when to choose it

An automatic drain operates on the principle of a mechanical linkage between the overflow cover on the side of the tub and the drain in the bottom. The lever (or rotating mechanism) on the overflow cover is transferred via a thin steel rod down to the drain, where it raises or lowers the stopper seal. Simply turning or pressing the cover on the overflow plate opens or closes the drain without having to reach into the tub.

This system is particularly practical for:

seniors or people with limited mobility who have difficulty reaching the drain at the bottom of the tub
an aesthetically clean solution, where you don't want to see any moving parts near the drain
tubs with a longer bottom, where the drain is far from the edge
bathrooms where simple and quick control of filling is required

A typical example is Automatic bathtub drain with overflow, chrome – a set that includes everything needed: drain, overflow cover with a lever mechanism, connecting hose, and seals. This complete set is designed to be installed without unnecessary problems even by a slightly more experienced DIY enthusiast.

Construction of an automatic drain – what's inside the set

A standard set of an automatic bathtub drain includes the following parts:

Drain basket – a ring with a strainer mounted in the opening in the bottom of the tub, usually 52 mm in diameter (standard bathtub drain)
Stopper seal – a movable part in the drain that mechanically opens/closes the drain
Overflow cover with a lever mechanism – mounted in the overflow opening on the side of the tub, contains the control lever
Connecting rod – a steel or plastic rod that mechanically connects the lever with the drain seal; its length is usually adjusted by shortening or telescoping
Overflow pipe – usually corrugated, flexible, connects the overflow with the drain; allows adaptation to different distances
Drain body – plastic or brass, contains the water seal and connection to the waste
Seals and nuts – rubber and plastic parts for airtight connections

CLICK/CLACK drain: simplicity and elegance

CLICK/CLACK (sometimes written as Click/Clack or just "clack") is a system where the drain in the bottom of the tub is controlled by direct pressing with the foot or hand. The first press pushes the seal in and closes the drain (water stays in the tub). The second press releases it and opens the drain. The mechanism is usually purely mechanical – it works on the principle of a locking pin in a groove, similar to push-button pens or furniture closing systems.

The advantage of CLICK/CLACK is its extraordinary simplicity of construction: no levers, no connecting rods. The overflow cover serves only to cover the overflow opening and carries no mechanical function. This has implications for installation – it is significantly simpler. On the other hand, control requires reaching the drain in the bottom of the tub, which may be less convenient for some users.

An example is CLICK/CLACK bathtub drain, with removable drain – a practical choice for any standard tub where the bottom is accessible. The removable drain also allows for easy cleaning without dismantling the drain.

What you need before installation: tools and preparation

Before the actual installation, prepare the following. You will need the following tools:

Adjustable wrench or a combination of flat and cross-head screwdrivers
Sealing compound (silicone) or Teflon tape – depends on the specific set
Scissors or a pipe cutter for cutting flexible pipe (for the automatic model)
Surface degreaser (isopropyl alcohol) for perfect silicone adhesion
Clean cloth
Optional: hex key (for siphons with a hexagonal nut)

Material-wise, it is important to verify:

Drain hole diameter in the bath – standard is 52 mm, less commonly 62 mm. If you are unsure, measure the hole before ordering the siphon. More on drain hole diameters can be found in the article What drain diameter do I need: DN32, DN40 or DN50?
Distance between the drain and the overflow – critical dimension for the automatic model; most sets cover the range of 270–400 mm, but there are also baths with non-standard distances
Bath base height – determines how much space you have under the bath for the siphon and connection to the sewer pipe. Minimum required height is usually 150–180 mm
Bath material – acrylic, cast iron, steel. With cast iron and steel, the wall thickness is greater, which affects the length of the screws and the depth of the screwing

Step-by-step installation of an automatic bath siphon

Installation of an automatic siphon is more complex than CLICK/CLACK, so we will go into it in more detail. It is a task that most skilled DIYers can complete in 60–90 minutes, but it is important to proceed systematically.

Step 1: Preparation and checking the parts

Unpack the set and check the contents according to the attached instructions. With an automatic siphon, you should have: the siphon body, drain basket with a grid, stopper mechanism, overflow cover with a lever, connecting rod, flexible overflow pipe, rubber seals (usually 3–5 pieces), plastic or metal nuts for tightening, and optionally silicone sealant. If any part is missing, do not start the installation – it is much easier to return an incomplete set before installation.

Step 2: Installing the drain basket into the bath bottom

Place a rubber gasket under the drain hole in the bath bottom. From above, place the drain basket with the grid on the gasket. From below (under the bath), fit another gasket and tightening nut. Now comes the stopper mechanism – either you screw it into the basket body with a thread, or you insert it into the basket and secure it (depends on the specific set). Tighten the nut by hand, then tighten it with a wrench – not too hard, because the rubber gasket can easily be squeezed out. Approximate tightening force: 3–4 Nm, which corresponds to a firm grip with one hand on the wrench.

Step 3: Installing the overflow cover with lever mechanism

Before installation, measure the actual distance between the centers of the drain hole and the overflow hole on your bath. This number will be needed when adjusting the connecting rod. Most sets have an adjustable rod in the range of ±30–40 mm. Adjust the rod to the correct length with a screw or adjusting element before installation – it is much easier while you still have the set in your hands. Insert a rubber gasket into the overflow hole, fit the overflow cover, and tighten it with a nut from inside the bath.

Step 4: Connecting the connecting rod to the stopper mechanism

This step is technically the most demanding, as you are working in a limited space. Lower the rod through the overflow cover so that its lower end catches the stopper mechanism in the drain basket. In some sets, the rod runs through the overflow pipe, in others it is separate. Move the lever on the overflow cover to check whether the closure actually moves. If the closure does not move or the lever moves freely, the rod needs to be shortened or lengthened. This adjustment sometimes requires 2–3 attempts.

Step 5: Connecting the overflow pipe and siphon body

Cut the flexible overflow pipe to the correct length – it must not be too long (it would create a loop and slow down the drainage), nor too short (stretching would cause a leak). Secure the pipe to the overflow outlet of the siphon and to the bottom of the overflow cover with screws. Connect the siphon body to the drain basket – with a thread or a push-fit connection. Check that all seals are properly seated.

Step 6: Connecting to the sewer and testing for leaks

Connect the siphon outlet to the sewer pipe. A standard bath drain has DN 40 or DN 50. The connection can be direct and rigid (if you have direct access to the sewer pipe), or via a flexible pipe for less accessible drains. After connecting, fill the bath with at least 10 cm of water, close the stopper, and let it stand for 5 minutes. Check all connections from inside and outside. Then open the stopper and observe the drainage speed – the whole bath should drain within 3–5 minutes. If any moisture appears anywhere, tighten the corresponding seal.

Installation process for CLICK/CLACK siphon

Installation of a CLICK/CLACK siphon is significantly simpler, as the entire phase of adjusting the connecting rod and mechanical connection to the overflow is omitted. The basic process is as follows:

Step 1: Installing the drain basket with CLICK/CLACK closure

Identically to the automatic model, insert a rubber gasket under the drain hole, fit the basket with the grid, and tighten the lower nut. The difference is that the CLICK/CLACK closure (movable piston) is part of the drain basket – it is either directly integrated or inserted into the basket and screwed in as a second step. Test the closure by pressing with your finger: the first press locks it down (closed position), the second releases it up (open position). If the mechanism does not move smoothly, check whether the closure is properly centered and not mechanically blocked by the gaskets.

Step 2: Installing the overflow cover

The overflow cover in the CLICK/CLACK system is a decorative-functional element without mechanical connection. It is sufficient to install it into the overflow opening via a rubber gasket and secure it with a clamping nut. No length adjustment, no mechanical calibration needed.

Step 3: Connecting the overflow pipe, trap and connecting to the sewer

The flexible overflow pipe connects the overflow to the trap. The procedure is the same as with the automation – correct length, no unnecessary loops, correct gaskets. Connect the trap to the sewer and perform a water tightness test.

Advantage of the removable outlet in CLICK/CLACK

Many CLICK/CLACK traps offer so-called removable outlets – the closure itself can be easily removed without tools, by turning or pulling. This is an enormous advantage when cleaning: hair, threads and other dirt are caught precisely on the outlet closure and can be removed in a few seconds. With traditional solutions, cleaning is significantly more time-consuming. The topic of trap cleaning is also covered in the article How to clean a clogged trap without chemicals.

Most common installation errors and how to avoid them

Over years of experience with custom installations, I have seen recurring errors. Here is a list with specific solutions:

Error 1: Over-tightening of gaskets

Rubber gaskets are soft and under excessive force they deform or are pushed out of the groove. Result: the trap leaks. Correct procedure: tighten by hand to a firm position, then only a quarter turn with a wrench. If it still leaks, the problem is not in the tightening force, but in the gasket position or its quality.

Error 2: Incorrectly set length of the connecting rod (with automation)

If the rod is too long, the closure will never fully open – water drains slowly or not at all. If it is too short, the closure will never fully close and water cannot be stopped. Correct setting: when the lever is pressed down (closure closed), the closure must not be visibly raised in the outlet basket. The control should have two clearly distinguishable stable positions without play.

Error 3: The overflow pipe is too long and forms a loop

A loop in the pipe holds water and dirt – an unintentional water seal forms at the wrong place, which slows down the drainage and eventually causes odors. Always cut the pipe to the actually needed length with a downward slope towards the trap.

Error 4: Using a wrong gasket or missing gasket

Some installers omit one gasket with the idea that "the rest will be sealed with silicone". Silicone is not a substitute for a structural gasket – it does not have the necessary mechanical strength and eventually detaches. Every gasket from the set has its place.

Error 5: Installing the trap without access for inspection

If you place the bathtub right next to the wall or without doors, pay attention to access to the trap. The law states that every closure on the piping must be accessible for service. In practice, it happens that the trap is installed perfectly, but at the first malfunction, you have to break the tiling. Always plan an inspection opening or at least a removable side panel of the tub.

Error 6: Connecting to the sewer without sufficient slope

The drainage pipe from the trap to the sewer riser must have a minimum slope of 2 % (2 cm per 1 meter). Without slope, water stands in the pipe, dirt accumulates and odors penetrate back. If the tub is low and slope is not possible, you use a flexible pipe with minimal slope or coordinate the trap position.

Trap materials: chrome, plastic, brass – what and when

Bathtub traps are available in several material versions. The visible parts (outlet basket, overflow cover) are made of brass with a chrome surface or stainless steel in quality products. The invisible parts of the trap body are mostly made of plastic (ABS, PVC) or brass in premium sets.

Chrome-plated brass – durable, long-lasting, aesthetically valuable. Ideal for representative bathrooms. Disadvantage: higher price.
Plastic (ABS) – light, cheaper, just as tight when properly connected. Disadvantage: less resistant to mechanical damage and UV radiation (but the sun does not reach it under the tub).
Stainless steel – most resistant to corrosion, hygienically problem-free. Common in floor drains and gutters.

More on this topic can be found in the article Stainless steel, brass or plastic: what material to choose for drainage technology in the bathroom?

Bathtub trap and floor drain: when to use which

Sometimes customers ask if they can use a floor drain or inlet instead of a bathtub trap. This combination makes sense in walk-in tubs or in tubs built into a shower area, where the floor around the tub also drains. In standard situations, the tub always has its own trap directly in the bottom.

If you are solving the drainage of a shower area together with the tub, you may be interested in products such as Flexible – Floor gutter with edge for perforated grid and adjustable wall collar, length 850 mm or double-sided floor gutter, 750 mm, DOUBLE9 FIT and GO, stainless steel. The adjustable wall collar on the gutter is a special topic that is discussed in the article Adjustable wall collar on floor gutter: when do I need it and how does it work?

For shower areas, different drainage rules apply than for tubs – more on this you will read in the article Floor gutter vs. floor inlet: what is better for a shower area? or in Installation of a floor gutter step by step: slope, position, connection.

Dimensional schemes and standard values

For a successful installation, it is important to know several key dimensions that repeat as standards in bathtub traps:

Diameter of the outlet hole in the bottom of the tub: 52 mm (the vast majority of European tubs), less commonly 62 mm
Distance from drain to overflow: usually 270–400 mm (measured from the centers of the openings)
Diameter of the trap outlet: DN 40 (40 mm outer diameter) – standard for a tub, sometimes DN 50 in older installations or on the explicit request of the designer
Minimum height of the tub base for a standard trap: 150 mm (some compact traps work at 120 mm)
Slope of the waste pipe: minimum 2 %, recommended 3 % (3 cm drop per 1 meter length)

How to choose the right set – summary of criteria

When choosing a bathtub drain, I recommend making your decision based on the following questions:

Who will use the bathtub? – Seniors or people with mobility limitations clearly prefer an automatic system with control from the overflow plate. Families with children or younger users can safely choose CLICK/CLACK.
What is the distance from drain to overflow? – If it is non-standard (under 270 mm or over 400 mm), check the compatibility of the specific set.
How high is the bathtub above the floor? – For a low base (under 150 mm), look for a compact drain or a solution with a side discharge.
What is the material of the visible parts? – Match it with the rest of the bathroom fittings (chromium faucet = chromium drain).
Do you need filling via the overflow? – Some sets have a water supply in the overflow cover (combination with a filling faucet), most do not.

In the category of drainage technology, you will also find other solutions including floor drains and gutters. For example, Floor drain with a chrome grid 12×12 cm, DN 40, brass is suitable for shower enclosures and terrace bathrooms, not for bathtubs – I mention it for context in complex renovations, where the bathroom is solved comprehensively. A wider selection and help with choosing is also offered in the article How to choose the right drain: sink, bathtub or shower?

Maintenance and preventing problems

Even a properly installed drain requires regular care. Basic recommendations from practice:

Once every 2–3 months, remove the strainer and clean it of dirt (hair, soap scum)
With a CLICK/CLACK drain with a removable outlet, remove and clean it – the whole operation takes less than a minute
Once a year, check the visible seals for cracks or hardening
If you hear gurgling during drainage, it is a sign of insufficient slope or partially clogged piping
If an odor appears, check the water seal – in bathrooms with irregular use, the water in the trap may dry out

If a problem occurs despite maintenance, I recommend the article Drain smells or water stands: causes and solutions and How to clean a clogged drain without chemicals from our Knowledge Center. Alternatively, see Common questions about drainage technology: drains, gutters, inlets and outlets.

Frequently asked questions (FAQ)

Is the installation of a bathtub drain a job for a DIY enthusiast or is a professional needed?

A CLICK/CLACK drain can be easily installed by a skilled DIYer with basic tools – it is a simple screw-on installation. An automatic drain is slightly more complex (setting the rod), but still does not require an plumber. I recommend a professional if you have non-standard dimensions, if access to the sewer is problematic, or if you are unsure about connecting to the waste.

Can I replace only the outlet seal without replacing the entire drain?

Yes, in most modern drains, outlet seals are standardized and can be replaced separately. In a CLICK/CLACK drain with a removable outlet, it is specifically designed for this – you only replace the movable piston, the rest remains. In older sets, this is not always possible, as the mechanisms were proprietary.

Why does the lever on the overflow plate stick or jam?

The most common cause is lime scale or soap residue on the connecting rod. Solution: remove the overflow cover, take out the rod and mechanically clean the deposits. Soaking in a lemon acid solution for 30 minutes also helps. If the problem is mechanical (broken rod, worn joint), the set usually cannot be repaired – the entire overflow mechanism must be replaced, which is a standard spare part.

Can I use silicone instead of rubber seals?

Silicone is used for additional sealing, not as a replacement for rubber seals. A rubber seal has a precisely defined hardness and elasticity, which allows it to adapt well to the surface when tightening the nut. Silicone can be applied additionally on the chrome basket before installation (outer ring for aesthetics), but never instead of the internal seal. An exception is when the seal is completely missing and silicone is a temporary rescue solution – but you should consider it temporary and soon replace the missing seal.

How do I check if my bathtub drain is fully functional after installation?

We always perform a so-called double test: the first is static – close the outlet, fill the bathtub at least to the ankles and let it stand for 5 minutes. If the level does not drop, the seal is working. Then check the connections under the bathtub with a flashlight – you must not see even a single drop of moisture. The second test is dynamic – open the outlet and observe the drainage speed. A bathtub with a volume of 180 liters should drain in 4–5 minutes. If it drains longer, check the setting of the seal and the slope of the waste pipe.

What is the difference between a bathtub drain with a direct and a side discharge?

Drains with direct discharge (the outlet neck points straight down) are suitable for bathtubs with a sufficient base height (at least 150–180 mm), where the pipe goes directly through the floor. Drains with side (horizontal) discharge lead water to the side – they are suitable for low bathtubs or built-in basins, where floor space is limited. The choice depends on the specific situation; always check the type of outlet the set has when ordering.

Conclusion: professional installation is the basis for long-term trouble-free operation

A bathtub drain – whether automatic or CLICK/CLACK – is technically not demanding, but a detail-rich part of the bathroom installation. The difference between a drain that leaves you in peace for 15 years and one that smells, leaks or jams is not in the choice of brand, but in the thoroughness of the installation: correct seals in the correct places, correct rod length, sufficient slope of the outlet and availability for possible service. If you get these things right during the first installation, the bathtub drain will disappear from your radar for many years – and that is exactly what you want from it.

Do you have a question about this topic?

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