How to choose the right Elektrobock timer for your home

We are still preparing products.

But you can look at other categories.

How to choose the right Elektrobock timer for your home

Timers are among the simplest, yet most effective tools for saving energy in the home. Despite this, many people spend an unnecessary amount of time searching for the right product – and not uncommonly end up with something that either doesn't fit their installation or doesn't control the appliance with sufficient accuracy. The brand Elektrobock has several different types of switches in its portfolio, each intended for a slightly different use case. This article will help you navigate the differences, understand what you actually need, and choose a specific model without unnecessary confusion.

I'm writing this from the perspective of someone who has seen these products installed in dozens of homes – from small apartments to family houses with boiler rooms, garden lighting, and cooling boxes in the basement. Each scenario has its own specifics, and that's exactly what I'll focus on in the following lines.

Why a timer at all and not just habit?

Before choosing a model, you need to honestly answer the basic question: is it worth it? From practice, I know that most people buy a timer for one of these reasons:

Outdoor or staircase lighting – they want the lights to be on only when needed, without the need for manual switching off.
Electric heater or heating – for example, a bathroom infrared heater that should be on only from 6:30 to 7:30 in the morning.
Aquarium or terrarium – precise switching of light according to the biological rhythm of the animals.
Garden pump or automatic irrigation – switching at specific times without human intervention.
Water heater or storage tank – heating only during the low electricity tariff period (night tariff).

In all these cases, the investment in a timer pays off very quickly – sometimes literally within months. A water heater programmed for the night tariff can save dozens of euros a year, a garden pump that only turns on in the morning and evening will extend its lifespan and reduce consumption.

Basic classification of Elektrobock timers

Before we look at specific models, it is important to understand that Elektrobock offers timers in several physical forms. Each form has a different installation method and is suitable for a different type of situation.

In the knowledge center you will also find a separate article Timer under the switch vs. on the DIN rail: which type to choose, where this division is discussed in even more detail. For the purposes of this guide, we will focus mainly on the series of switches under the switch (CS3) and remotely controlled sockets – that is, products suitable for average home users without deep electrical knowledge.

Series CS3: switch under the switch – the golden mean for the home

Switches of the CS3 series are designed to fit directly into a standard installation box (electrician's box in the wall) in place of a classic switch. The outer cover (frame + button) remains the same as you know – usually in the standard of Legrand, Schneider, ABB or compatible with common cover frames. Installation therefore does not require any wall breaking or new wiring.

This series contains several models that differ in the number of channels, maximum load and display functions. Let's go through them one by one.

CS3-1: basic model for simple tasks

Timer switch under the switch CS3-1 is a single-channel switch with a digital display. It controls one output circuit and allows setting up to 10 different switching events (on/off) spread throughout the week. Each event can be set with an accuracy of 1 minute.

The maximum switching power with resistive load is 3,500 W (16 A / 230 V). This practically means that it can easily handle:

Bathroom infrared heater up to 2 kW
Common incandescent, LED or fluorescent lights
Electric water heater up to 3 kW
Aquarium technology (pump + heating rod + light together)

CS3-1 is ideal for scenarios where you need to switch one appliance according to a fixed weekly program – for example, garden lighting, night security light at the entrance or an electric garden boiler with a night tariff.

CS3-1B: same function, different cover design

Timer switch under the switch CS3-1B is functionally identical to model CS3-1 – same power, same number of programs, same setting accuracy. It differs only in the design of the outer cover, which better fits certain interior electrical installation standards. If you are equipping an interior with a specific design series of sockets and switches and you care about visual harmony, CS3-1B may be the right choice without having to sacrifice any function.

From the point of view of selection, the decision between CS3-1 and CS3-1B is therefore purely an aesthetic matter – they are functionally identical.

CS3-2: dual-channel switch for more demanding scenarios

Timer switch under the switch CS3-2 adds a second independent output circuit. Both channels have their own time program and can be programmed independently of each other. The display shows the current time and the status of both outputs.

Where does this make real sense? For example:

Deck with lighting and garden pump – the lighting turns on in the evening and turns off at midnight, the pump runs for an hour in the morning and for an hour in the evening.
Bathroom with two circuits – the infrared heater turns on in the morning, the fan (humidity extraction) runs separately according to a different program.
Garage with lighting and electric bicycle charger – the charger runs only at night during the low-cost tariff period, the lighting operates as needed.

CS3-2 fits into the same installation box as single-channel models, which is a big advantage – no additional drilling is needed. The maximum power per channel is the same as with CS3-1, i.e., 3,500 W at resistive load.

CS3-4: four channels for complex automation

Timer switch under the switch CS3-4 is the top model in the series with up to four independent output channels. Each channel has its own weekly schedule and the display allows an overview and setting of all four outputs.

Typical use of CS3-4 in a family home:

Channel 1: exterior lighting (gate, entrance)
Channel 2: pool pump (water filtration)
Channel 3: garden irrigation pump
Channel 4: electric water heater (night tariff)

All controlled from one place, from one installation box, with one display. For a family home builder or for someone who wants to properly automate the household without investing in smart home systems, CS3-4 is a very interesting solution at a reasonable price.

Remote-controlled socket WS101: when you don't want to deal with installation

Remote-controlled socket WS101 is a completely different type of product – it is not a classic timer switch with a program, but a wireless-controlled socket. You plug it into a standard wall socket and use the included remote control to switch the appliance connected to it. No installation, no electrician, no drilling.

WS101 is the right choice in these situations:

You want to control an appliance remotely without physical access to the socket (e.g., a table lamp behind furniture).
You need a temporary solution – for example, in a rental property where you don't want to interfere with the installation.
You want to be able to turn an appliance on or off from a couch or bed.
You are dealing with seasonal use – Christmas lighting, a summer fan, Christmas.

WS101 is not equipped with an internal timer program – it is switched exclusively manually via the remote control. If you therefore want automatic switching according to hours and days, you need to choose one of the CS3 models. Both product groups – remote sockets and switches under switches – complement each other and many households combine them.

How to decide: practical decision tree

Based on practical experience, I have compiled a simple procedure that will help you choose the right product without unnecessary hesitation:

What else influences the choice besides the number of channels

Selecting based on the number of channels is indeed a basic step, but not the only one. You also need to consider several other factors that practically determine whether the switch will reliably function for the next 5 years.

Maximum power of the appliance

Each switch has a specified maximum switching power. For the entire CS3 series, this is typically 3,500 W (16 A) for purely resistive loads (light bulbs, heating coils, boilers). However, be careful with inductive loads – motors, pumps, air conditioners. With these appliances, you must account for a lower allowable value, as the motor's starting current can be several times higher than the rated power.

Practical rule of thumb: when switching a motor or compressor, expect a starting current of 4–8 times the rated current. A pump with a power of 500 W can thus temporarily draw the equivalent of 2–4 kW at startup. A switch will usually survive this if it is dimensioned for at least three times the motor's rated power.

More information on maximum power and load examples can be found in the article What is the maximum power that a timer switch or Elektrobock socket can handle in this knowledge center.

Backup battery and program retention during power outages

This is a question customers often ask: "What happens if the power goes out?" CS3 switches are equipped with an internal backup battery (or capacitor) that maintains the set time and program during short-term power outages. The backup duration varies by model and battery condition – it is usually several hours to days. In the case of long-term power outages (e.g., several days of absence in a cabin without a power grid), after power is restored, always check whether the clock shows the correct time.

Compatibility with installation boxes and faceplates

Technically speaking, CS3 switches are designed for standard round or square installation boxes with a minimum depth of 35 mm (ideally 45 mm or more). The modular mechanism is compatible with a wide range of faceplates from common manufacturers – Legrand, Schneider Electric (Unica, Mureva), ABB, Opus, etc. Always check the depth of the box before purchase, especially in older apartments, where the boxes may be shallower.

Accuracy and flexibility of programming

The entire CS3 series allows setting switching events with a precision of 1 minute, which is more than sufficient for a household. Programming is done directly on the device display using buttons. A detailed setup procedure can be found in the article Programming a weekly switching schedule on Elektrobock switches – I recommend reading it before the first configuration.

Typical practical scenarios: concrete examples of use

To go beyond theory, let's look at specific situations I encounter most often.

Scenario 1: Family house, pool technology + outdoor lighting

The customer had a pool with a filtration pump (750 W), a disinfection UV lamp (100 W), and outdoor LED lighting for the terrace (300 W). Originally, everything was switched manually, and the pump was often forgotten to be turned off at night. Solution: CS3-2 – channel 1 for the pump + UV lamp (total 850 W, switching 6:00–9:00 and 17:00–21:00), channel 2 for the terrace (switching 20:00–23:30). Installed in an existing box near the pool, the whole process took the electrician about an hour.

Scenario 2: Apartment, electric heater in the bathroom

A lady in an apartment had a 1.5 kW infrared heater in the bathroom. She did not want to leave it on when not in the bathroom, but also wanted the bathroom to be warm when she woke up. Solution: CS3-1 – set to turn on at 6:00 and off at 7:30 every workday, different program on weekends (9:00–10:30). Simple installation, energy consumption dropped by an estimated 40 % compared to the previous usage method.

Scenario 3: Garden cabin, seasonal operation

The cabin owner wanted to automatically switch the exterior lighting (100 W LED), an e-bike charger (300 W), and a small pump for the well (400 W), all independently. Solution: CS3-4 – three channels in active use, the fourth channel as a reserve for future expansion (e.g., an outdoor grill with an electric igniter). The whole solution in one box, clear display, no need to reach for a separate distribution board.

Scenario 4: Temporary solution in a rental

The tenant wanted to control a reading lamp and a desk fan without getting up. Since any modifications to the installation were prohibited, he opted for WS101. The socket plugged into a standard wall socket, the remote control on the nightstand. After the lease ended, the entire solution was packed up and taken with him.

Installation: what you need to know in advance

Mounting a switch under a switch is a relatively simple task, but you should be aware of certain technical requirements. Always keep in mind that the installation of electrical devices in fixed installation (i.e., inside the wall, in a box) should be carried out in accordance with applicable standards and ideally by a qualified person. In Slovakia, this refers to STN EN 60364 and related regulations.

Short technical requirements for installing CS3:

Installation box: minimum diameter 60 mm, minimum depth 35 mm (ideally 45 mm)
Cable cross-section: minimum 1.5 mm² (for circuits up to 16 A), recommended 2.5 mm²
Circuit protection: maximum 16 A (according to the switch's rated current)
Earthing (PE): the switch must be connected to the protective conductor

A detailed installation procedure with illustrations can be found in the article Installation of the CS3 timer switch under a switch: step-by-step guide – including how to safely disconnect the power and check the correctness of the wiring before turning on the circuit breaker.

Common mistakes when choosing and what to watch out for

Over the years I have seen really various mistakes. Some were innocent, others caused problems. Here is a list of the most common ones:

Mixing up capacity and performance: Buying CS3-1 with the intention of connecting a 6 kW water heater. Maximum power is 3.5 kW – you won't manage that. For more powerful appliances, you need a DIN switch with a higher rated current (e.g. CS4-16). More about DIN rail switches can be found in the article Installation of the Elektrobock timer CS4-16 on a DIN rail.
Shallow installation box: In panel houses from the 70s, boxes are often only 25–30 mm deep. Module CS3 fits there only with difficulty or not at all. Always measure the depth before buying.
Failure to reset the backup program after a power outage: After each longer power outage, check that the clock is set correctly. Wrong time = switching at the wrong time.
Switching high inductive loads without reserve: Air conditioners, more powerful pumps, compressors – always choose a switch with sufficient reserve compared to the appliance's rated power.
Mixing up WS101 with a full-featured programmable switch: WS101 does not have its own timer program. If the customer wants automatic switching, WS101 is not sufficient.

How long will the Elektrobock timer last?

Elektrobock is an established Czech brand with a long tradition in the production of control technology. In practice, CS3 switches last 10–15 years without problems under normal use. A weak spot is the backup battery – it typically lasts 5–7 years and after it runs out, the switch does not lose its function, but it no longer retains the settings during a power outage. Battery replacement is simple and the battery is available in any electrical store.

Another potential source of problems are the output contacts – when switching inductive loads (motors) frequently, they may wear out after years. Signs and solutions to faults are described in a separate article Common faults of Elektrobock timers and their solutions in this knowledge center.

Product combinations: what works together

In some households, it makes sense to combine several types of switches. For example:

CS3-4 + WS101: CS3-4 controls fixed installed appliances (water heater, pool, lighting), WS101 is used for convenient control of a portable appliance (fan, lamp) without the need to get up.
CS3-2 + CS3-1: When one circuit is not enough and CS3-4 is excessive – for example in a smaller apartment with a garden.

To pair and set up WS101 with a remote control, read the article Remote-controlled socket WS101: setup and pairing with a remote control, where the whole process is explained step by step.

Price vs. value: is it worth saving on a cheaper model?

A question I hear quite often: "Is the cheapest analog switch from the home center for 5 euros enough for me?" It depends on the situation. Cheap analog switches with mechanical pins have an accuracy of only 15 minutes and usually only a 24-hour cycle without distinguishing between workdays and weekends. This simply does not suffice for many scenarios.

Digital switches CS3 are accurate to the minute, have a 7-day weekly program, backup power supply and more reliable contacts. The price difference between a cheap analog and a quality digital switch is in the range of tens of euros – for appliances where you save energy every day, the investment pays off very quickly.

Frequently asked questions (FAQ)

Can I install CS3 myself, without an electrician?

According to current Slovak regulations (Act No. 251/2012 Coll. on energy and STN 33 2000), it is stipulated that interventions in fixed electrical installations (including replacement of switches in installation boxes) should be carried out by persons with professional qualifications. In practice, many homeowners do this type of work themselves, but you should be aware of the responsibility and risks. If you are unsure, let an electrician do the work – installation of CS3 is a matter of 30–60 minutes for a professional.

What happens to the program after a power outage?

Switches CS3 are equipped with a backup power supply (battery or supercapacitor), which maintains the set time and program during short outages. During longer outages (several hours to days), the settings may be lost – after power is restored, always verify the displayed time and, if necessary, manually correct it.

Can I use switch CS3 to control LED lighting or energy-saving lamps?

Yes, LED lights and compact fluorescent lamps (CFL) are without problems for switches CS3. These loads typically have very low power and the switch can handle them without any limitations. The only thing to watch out for are very cheap LED strips without quality power supplies – these can generate interference when turned on, which is usually not a problem with the switch itself, but with the LED strip itself.

How many switching programs can I set on CS3-1?

CS3-1 supports up to 10 independent switching events (pairs of on/off) arranged in a weekly cycle. Each event can be assigned to specific days – for example only workdays, only weekends, or any combination of days. For most home scenarios, 10 programs are more than sufficient.

Is WS101 suitable for outdoor use?

No. WS101 is designed for indoor use in dry environments (protection class IP20). For outdoor use, you need switching elements with at least IP44 or IP65 protection. External appliances (garden pump, outdoor lighting) are better switched via a permanently installed switch CS3 located in a protected indoor space.

Can I use CS3-4 in a workshop or garage, not just in the living area of the house?

Certainly. CS3-4 is adapted to the standard supply voltage of 230 V AC and is mounted in standard installation boxes. Its use in a garage or workshop is very practical – for example for automatic switching of lighting, dehumidifier fan, battery charger or garden equipment. It is important that the installation location is dry and meets at least IP20 protection (if there is no socket in the distribution board with higher protection).

Conclusion: choosing according to real needs

Choosing the right Elektrobock timer for a household is not complicated if you answer two key questions in advance: how many independent circuits do I need to control, and do I want automatic time switching or just manual remote control? From this it follows whether you reach for a single-channel CS3-1 (or design CS3-1B), a two-channel CS3-2, a four-channel CS3-4, or a flexible remote socket WS101.

For each of these products, it is true that they are proven, reliable devices with a long service life and simple operation. Proper installation, appropriate load dimensioning and initial program setting – these are the three things that matter most. The rest is just daily comfort and satisfaction that the household is working even when you are not thinking about it.

Do you have a question about this topic?

Can't decide or are you dealing with a specific situation in your household? Write to us – we are happy to help.