Smoke detectors

General information on smoke alarms and the smoke alarm obligation

Smoke detectors: For the life-saving head start

Why is a smoke detector essential? Or in other words: Why do you fasten your seatbelt when driving?

In principle, what the seat belt is in your car, the smoke detector is at home. A smoke detector detects smoke and sounds the alarm in time. This is especially important at night, because we can't smell anything when we are asleep. Escape is then often no longer possible. Just a few breaths of the faint and often very toxic smoke can lead to death by suffocation. Smoke is fast. Within a very short time, the toxic gases produced by the many plastics in households spread. Usually there are only 2 to 4 minutes left to escape. Smoke is dark and makes breathing difficult, so that you can lose your orientation even in your own house.

In the event of a fire, smoke alarms not only give you the head start you need to get yourself and your family to safety and call the fire brigade. Smoke detectors save your life.

Worth knowing: Smoke alarm device

Why should there be a fire in my flat?

The forgotten iron, bread crumbs in the toaster, burnt candles in the decorative bowl, food on the cooker or overloaded multiple sockets - fires have many causes and unfortunately often devastating consequences.

Almost every day there is a fire somewhere in Germany. A house fire can affect anyone. Often it is not even caused by carelessness or human error. The increased number of household appliances increases the risk of technical defects and thus also the risk of fire.

Smoke detectors warn us in time and this is especially important at night when we are asleep, because we don't smell anything when we are asleep. Smoke detectors give us the opportunity to take fire-fighting measures with a fire extinguisher if necessary and to keep ourselves, the family and the neighbours safe. Every large fire starts small. An incipient fire can develop into a major disaster within a few minutes.

A smoke detector is a small investment to protect your life and that of your family.

Is it still allowed to smoke in the flat if you have installed a smoke alarm?

Yes, no alarm is triggered for normal cigarette consumption. If several people smoke heavily at the same time, an alarm may be triggered. In this case, simply mute the detector and ventilate the room.

How loud are smoke alarms?

Smoke alarms are very loud. Quality smoke alarms according to DIN EN 14604 reach 85dB (A) at a distance of 3 metres. This means that in the event of a fire, they can rouse people from their deepest sleep.

Smoke alarm or smoke detector?

Both terms mean the same thing. However, the technically correct term is smoke alarm. However, the word smoke detector is used by most people in everyday use.

What does the smoke alarm obligation mean?

Is there an obligation to install smoke alarms?

In federal states with compulsory smoke alarms, there is such an obligation. Smoke alarms sound in time in the event of a fire. Even sleeping persons are roused from their sleep by the loud alarm. Remember, the sense of smell also sleeps during sleep. Smoke alarms are therefore life-saving. Smoke alarms should therefore always be installed, regardless of any legal obligation.

The smoke alarm obligation is regulated by law in the building codes of the individual federal states.

Do I have to comply with the smoke alarm obligation?

Yes, the smoke alarm obligation is binding. If you do not comply with this obligation, you are acting illegally. Even if the obligation is not currently controlled, it can still become critical if personal injury occurs in a fire. This could have far more unpleasant consequences in terms of civil law and insurance. From this point of view, everyone decides correctly to simply install smoke alarms.

Who is responsible for installing smoke alarms in federal states where smoke alarms are mandatory?

As a rule, owners/landlords are responsible for installing smoke alarms. In Mecklenburg-Western Pomerania this is regulated differently. Here, the tenant as "owner" is explicitly responsible for the installation of detectors.

Who has to maintain the smoke alarms in federal states with compulsory smoke alarms?

As a rule, the landlord is responsible for maintenance if the state building code does not stipulate otherwise.

In the following federal states, however, maintenance is the responsibility of the tenant if the owner does not assume this duty:

  • Baden-Württemberg
  • Bavaria
  • Bremen
  • Hesse
  • Mecklenburg-Western Pomerania
  • Lower Saxony
  • North Rhine-Westphalia
  • Schleswig-Holstein

In federal states such as Hamburg, Saxony-Anhalt and Thuringia, the state building code does not regulate who is responsible for maintenance. Here, the responsibility for regular maintenance results from the owner's duty of care, which is anchored in tenancy law.

The landlord can transfer the obligation of installation and maintenance to the tenant in the tenancy agreement. However, the landlord must be satisfied that the tenant is capable of doing so. Since the landlord is liable if the detector does not work in case of fire, this approach is not recommended.

In Mecklenburg-Western Pomerania, the tenant is responsible for the installation and consequently also for the maintenance.

During maintenance, it must be ensured that the detectors are ready for operation. The maintenance must be documented in a log.

Who bears the costs for the installation of smoke alarms and their maintenance?

As a rule, the landlord bears the costs for the acquisition. Mecklenburg-Western Pomerania is currently an exception. According to §559 of the German Civil Code (BGB), the landlord may pass these on to the tenant at a maximum of 11% of the investment costs. If the landlord is also responsible for maintenance, he may apportion the maintenance costs to the ancillary costs.

May smoke alarms that have already been installed continue to be used?

Yes, existing smoke alarms may generally continue to be used. As the owner, it is recommended to convince oneself of the proper equipment and installation as well as the operational readiness and to document this. However, the owner is not obliged to continue using the existing detectors.

If a combined fire detection and alarm system has already been installed, do smoke alarms still have to be installed?

No, if there are fire detectors in every bedroom and children's room as well as in the escape routes, the installation of smoke alarms can be dispensed with. However, the devices used must also comply with the relevant standards.

Do smoke alarms need to be interconnected?

No. However, in larger residential units it makes sense to interconnect the smoke alarms. For example, a fire in the basement would quickly alert the sleeping people in the attic.

Must the operational readiness of smoke alarms also be ensured during a holiday?

No. First and foremost, smoke alarms are intended to warn people in time if they are in the affected occupancy unit. Pay attention to whether disconnection is technically possible (see operating instructions).

Who pays for the costs of a fire brigade intervention in the event of a false alarm?

As a rule, interventions due to a false alarm are free of charge for the owner or tenant if the latter has not acted intentionally or with gross negligence.

What should be done for people whose hearing is impaired?

For people with limited perception, organisational measures may have to be provided or additional, suitable warning devices such as a flashing device and shaking pads may have to be used. However, the law only prescribes minimum protection with conventional battery-operated smoke alarms according to DIN EN 14604.

The owner is not obliged to pay the extra costs for such additional equipment. However, health insurance companies must cover the costs for special smoke alarms for the deaf. This is what the Federal Social Court decided in a ruling in June 2014 (Ref. B 3 KR 8/13 R).

Installation site

In which rooms must smoke alarms be installed?

According to the application standard DIN 14676 and according to the building regulations of the federal states with compulsory smoke alarms, smoke alarms must be provided in all bedrooms and children's rooms as well as guest rooms and corridors (and other rooms) that serve as escape routes.

Important: If the bedroom can only be reached via the living room, then a detector should also be installed in the living room. Remember that people sometimes fall asleep on the couch in front of the TV with candles burning, so a smoke alarm should definitely be installed here as well. Ideally, smoke alarms should be installed in every room of the flat except for the kitchen and bathroom so that you can be warned in good time.

Can smoke alarms also be installed in kitchens and bathrooms?

Smoke alarms should not be used in kitchens and wet rooms such as bathrooms, as the risk of false alarms caused by moisture and vapours is very high. In addition, the moisture would attack the electronics in the long term, especially in the bathroom. If you also want to monitor the kitchen, we recommend heat detectors. You will find out what you should do if the kitchen is also your escape route when you answer the next question.

What if the kitchen is my escape route?

If the kitchen is used as an escape route from bedrooms behind it, then the kitchen must also be equipped with a smoke alarm. In these cases, wall mounting, where the smoke reaches the detector later, can be useful. In this case, the smoke alarm must be suitable for wall mounting. Mount the detector according to the manufacturer's operating instructions.

Can the attic and cellar also be equipped with smoke alarms?

In principle, yes. However, note that high levels of dust, draughts, temperature fluctuations, etc. increase the risk of false alarms. Also pay attention to the ambient temperature. Most smoke detectors can be used from +5°C to +50°C and must not be exposed to large temperature fluctuations. Condensing water could affect the detector. It is best to ask a certified smoke alarm specialist.

Should staircases in apartment buildings be equipped with smoke alarms?

According to the application standard DIN 14676, generally used rooms such as cellars, attics and stairwells in apartment buildings are not directly assigned to a flat and are not intended for the permanent residence of persons. Therefore, it can be assumed that the persons have their full perceptive capacity and are able to detect fire hazards in time. For this reason, smoke alarms are not mandatory here.

Tip: Make sure that the stairwell is free of flammable items. Bicycles, prams, shoe cupboards, etc. do not belong here. The property owner is responsible for this.

Does a smoke alarm always have to be mounted on the ceiling or can it also be mounted on the wall?

Yes, smoke alarms always belong on the ceiling. Smoke rises and concentrates on the ceiling. Only here can it be detected effectively.

With wall mounting, smoke can only be detected at a later stage. Nevertheless, this can be useful in exceptional cases, e.g. if a smoke detector must be installed in the kitchen and this must also be used as an escape route. In this case, the detector must be approved for this purpose. This is documented in the manufacturer's operating instructions or there must be separate proof of suitability from the manufacturer.

The exact installation location on the wall must also be observed. In such cases, be sure to ask a certified smoke alarm specialist. They will be happy to help you.

Installation & operation

Why are there actually specialists for the installation of smoke alarms?

The professional installation of smoke alarms is regulated in the application standard DIN 14676. Certified specialists for smoke alarms according to this DIN know how fire smoke behaves and where the detector must hang. The DIN also regulates, for example, where detectors must be installed in narrow corridors, rooms with high ceilings and rooms with galleries. A certified specialist can also advise you competently and maintain your smoke alarm in accordance with DIN.

How do you install a smoke alarm?

Be sure to follow the manufacturer's installation instructions. When you have installed your smoke alarm device and subjected it to a final function test with a positive result, it is ready for operation.

Be aware that false alarms can be triggered by cooking fumes. In this case, mute the detector and ventilate. Attentive neighbours should inform you in such cases before you call the fire brigade. In the case of smoke detectors with replaceable batteries, you should know what to do in the event of a battery fault signal.

Also make sure that the smoke alarm must not be covered under any circumstances.

Why should a certified smoke alarm specialist install the detector?

A certified smoke alarm specialist knows the basic properties of fire smoke and can use this background knowledge to decide on the best way to install and maintain the right smoke alarm according to the manufacturer's specifications, taking into account the conditions on site.

How do I attach a smoke alarm device?

Here, too, the manufacturer's installation instructions and the installation surface must be considered. As a rule, the instructions prescribe mounting with two dowels and screws.

Adhesive pads are only used as a fixing aid, e.g. when fixing the detector with a "central screw". The adhesive pad is intended to prevent the base from twisting when the detector is inserted. This type of mounting may also only be carried out if the manufacturer permits it in his operating instructions. We accept no liability for adhesive pads or for the detectors attached with them. We also point out that the installer may also be held liable for restorative damage to ceilings caused by adhesive pads (e.g. if the detector is to be replaced or relocated).

If you attach the smoke detector with an adhesive pad and it falls down, the detector must no longer be used as it may be damaged and will no longer alarm in time in case of fire.

What do I do if I want to renovate the room where the smoke alarm is installed?

Remove the smoke alarm so that it does not become dirty due to painting work or a high level of dust and hang it up again after the work. It is important not to paint over or damage the smoke alarm device under any circumstances. Please note that the detector must be tested again after installation.

With radio-networked smoke detectors - such as the ST-630 - you must take care to unregister the detector from the network when removing it and to register it again when putting it into operation. If this is not done, the battery of the other smoke detectors in the network will be emptied rapidly as they constantly try to "find" the missing detector. In any case, you should always follow the operating instructions.

How long can a smoke alarm device be used?

According to the application standard DIN 14676, the detector must be replaced after 10 years, as the material usually fatigues and safety is no longer ensured.

The product standard DIN EN 14604 also stipulates a maximum period of use of 10 years.

How do I know if my detector is still working?

Simply press the test button. If the detector beeps and an LED (detector-dependent) flashes with a time delay, the functionality is confirmed.

How does a smoke alarm function?

As a rule, smoke alarms function according to the optical principle or scattered light principle:


Normal stateSmoke entry
In the smoke chamber, light rays are regularly sent from the light-emitting diode. In the normal state, these light rays do not hit the photo lens.If smoke enters the measuring chamber, the emitted light rays are refracted and hit the photo lens. The acoustic alarm is triggered.


Before an alarm is triggered, a certain smoke concentration must first be reached in the measuring chamber. This prevents light smoke, e.g. from cigarettes, from causing a false alarm.

State-of-the-art smoke detectors such as the FireAngel ST-620 and ST-630 detectors are equipped with a thermo-optical detection method for double security. The optical sensors measure the concentration of smoke particles, while the thermal sensors detect temperature changes. In this way, smouldering or liquid fires in particular, which do not form much smoke at the beginning, can be detected more quickly. A life-saving head start is created.

Maintenance and inspection

Why should I service the smoke alarm regularly?

Only a regularly maintained smoke alarm reduces false alarms and ensures safety. In states where smoke alarms are compulsory, annual maintenance is also mandatory. The manufacturer's operating instructions should also be followed.

Does the annual maintenance have to be carried out by specialist companies?

No. It is the decision of the person responsible for maintenance to follow the recommendation of DIN 14676 and to commission a certified specialist company to install and maintain the smoke alarms. Certified smoke alarm specialists are entrusted with the project planning, installation and maintenance of smoke alarms and have provided proof of their competence by passing an examination. They are also obliged to update their knowledge every 5 years. In addition, the certified specialist provides proof by means of a protocol that the legal obligation has been fulfilled. In the event of damage, the landlord/owner can thus present appropriate documentation.

How often does a smoke alarm need to be serviced?

Please refer to the operating instructions. They regulate how often and what needs to be done. In states where smoke detectors are compulsory, the detector must also be subjected to a functional and visual inspection once a year.

Does the maintenance have to be documented?

There is no legal regulation on this. However, it is recommended to do so. This way, in the event of a claim, it can be proven to the insurance company that the smoke alarm obligation has been complied with and that the obligatory maintenance has been carried out.

What does annual maintenance according to DIN 14676 look like?

According to DIN 14676, at least the following tasks must be carried out:

for standalone smoke detectors (non-networked detectors):

  • Check whether the unit is visibly damaged or inoperable
  • Check whether the unit displays signals indicating that, for example, the battery voltage is insufficient
  • Check that the smoke inlets are clear
  • Check that the alarm is audible at a sufficient volume 85dB(A) when the test button is pressed
  • Check that the detector is mounted correctly, i.e. check that there are no obstacles within a distance of
    0.5 m around the smoke alarm device that obstruct the penetration of smoke
  • Check that the use of the rooms has not changed, i.e. is the detector still in each bedroom and children's room and in the corridors that serve as escape routes

Additional task for interconnected detectors

  • Check whether the signal is passed on to all other smoke detectors

The functional test is always carried out in accordance with the manufacturer's operating instructions.


How long does a battery last?

This depends on the detector type. Smoke detectors with a replaceable battery must be replaced according to the manufacturer's instructions, while 10-year detectors have a permanently integrated battery that lasts at least 10 years before the detector needs to be replaced.

Smoke detectors indicate that the battery power is getting low by means of a signal tone and/or a light-emitting diode or light-emitting LED.

The battery life depends on many factors. Please note that dirt, incorrect operation and installation can affect the battery life and lead to false alarms.

Is there a removal protection for batteries?

Who hasn't experienced it: The batteries of the remote control are empty and a replacement is quickly sought; it would be practical to simply use the batteries of the detector. To ensure that this does not happen at the expense of safety, 10-year detectors are recommended. Here, the battery is permanently integrated and cannot be removed.

False alarms & faults

What is a false alarm?

A false alarm is when the detector detects smoke and sounds an alarm even though there is no fire. In this case, the alarm was triggered by another cause, e.g. hot frying.

In such a case, first make sure that there is definitely no source of fire. Then press the mute button (if present) or remove the battery. Remove the source of interference, e.g. by ventilating. Your muted detector will activate itself after approx. 10 min.

Some devices require the battery to be removed in such a case (the battery cannot be removed from 10-year detectors). Do not forget to reinsert it later to put the unit back into operation.

What is a malfunction alarm?

A malfunction alarm, which occurs very rarely with high-quality units, is when the unit no longer functions properly and it therefore triggers an alarm or a malfunction signal.

What to do in the event of a malfunction?

Malfunction alarms can have different causes. On our website you will find a checklist. First see if one of these causes is present in order to check whether there is a reason for complaint.

Quality, brands and products

What is the best place to buy a smoke alarm?

It is best to buy a smoke alarm directly from a specialist dealer. Here you will receive individual advice and, if you wish, also the installation as well as the documentation of the installation and, if necessary, maintenance. Contact us, we will be happy to give you the name of your local fire protection dealer. They will advise you comprehensively and competently on the subject of "fire protection".

Which models are recommended?

Generally, 10-year smoke alarms are recommended. They are equipped with a long-life battery, so there is no need to change it. Compared over the years, they are actually cheaper and protect the environment by using only one battery. In addition, they are equipped with other functions, such as a large mute button that can be operated from the ground with a broomstick.

How can I recognise a high-quality smoke alarm device?

A smoke alarm that may be traded in Germany today must comply with the product standard EN 14604 and be marked with the CE mark. However, the CE mark is not a quality standard. Therefore, we strongly recommend that you make sure that the detectors also bear a test mark from VdS or KRIWAN test centre. You can also recognise high-quality smoke alarms by the Q-label. This mark is for orientation purposes and identifies 10-year smoke alarms that have been specially tested for long-term use.

Important note

All information contained in this website has been researched with the utmost care. Nevertheless, it can only be provided expressly without any guarantee. Errors and omissions may occur.