Skip to Content

Working smoke detector can save you!

When a fire breaks out, fast action is vital. When a fire breaks out in a flat, temperatures as high as 300 to 400 degrees Celsius develop within four minutes and combustion gases fill the rooms, which means that your chances of survival are poor. A smoke detector detects the combustion gases at low concentrations and makes a loud sound.

When a fire breaks out in a flat, temperatures as high as 300 to 400 degrees Celsius develop within four minutes and combustion gases fill the rooms. Give yourself a chance of survival –  a working smoke detector can save you...

Smoke detector are compulsory in all homes, buildings in which people sleep and care institutions

Remember that you must also have a smoke detector in all holiday houses as well as outbuildings and similar where people sleep. You should also have smoke detectors in boats with cabins, caravans and campervans. Note that in these conditions, the service life of the detectors and their batteries, in particular, is shorter than normal. Smoke detectors in flats built after 2009 are connected to the mains and have batteries for backup. This also applies to holiday houses which have electricity. Having carbon monoxide alarms and gas detectors is recommended if there is a fireplace or gas appliances in the building.

Test your smoke detectors once a month

Testing is an important step to ensure that your detector works properly and is ready to operate.

smoke detectors installer

Change the batteries and replace old detectors 

Change the batteries at least once a year. Do this on a date that you can easily remember, such as the national smoke detector day (1 December), Christmas or the first day you spend in your holiday house. Always change the battery immediately if the smoke detector repeatedly gives a quiet beep. Always keep spare batteries handy.

Replace your smoke detectors every 5 to 10 years. The detectors do not last forever, and it is essential that you replace them regularly. Nowadays smoke detector manufacturers mark the recommended time for replacing the detector on its label as a ‘best before’ date. Always replace the smoke detector immediately if you have changed its battery and it still does not work.

Where should I place the smoke detector?

Smoke detectors should be placed

  1. in all bedrooms and other rooms used for sleeping
  2. on escape routes, including the hall
  3. in staircases and other areas with high ceilings

where to install smoke detector in a flat or house

Smoke and heat rise up, which is why the smoke detector should be placed as high as possible on the ceiling, at least half a metre away from any walls and other obstacles. Always follow the installation instructions of the smoke detector. 

If your flat or house is large, it is recommended that you have interconnected smoke detectors. It means that if one smoke detector is triggered, this will cause a general alarm across all the interconnected detectors. Do not install the detector on a wall, in the kitchen, in the vicinity of air vents or in a bathroom. This may cause the detector not to work, work incorrectly or become damaged.

One smoke detector can cover at maximum 60 m2 on a single floor

  • 1 detector is needed in a flat or house with a floor area of less than 60 square metres
  • 2 detectors in a flat or house with a floor area of less than 120 square metres
  • 3 detectors in a flat or house with a floor area of less than 180 square metres

In addition, each floor of the flat or house (including basements and attics) should have at least one working smoke detector.

Remember that smoke is even more dangerous than fire.

Two out of three fire-related deaths are caused by combustion gases.

When the smoke detector goes off – act fast!

The smoke detector detects smoke and alerts you before you can sense or notice anything. Even a small fire fills the flat with smoke very quickly.  A working smoke detector which is in the right place will alert you and wake you up. You only have two to three minutes to escape, try to put out the fire and call 112 for help. When the alarm goes off, act fast!

If the smoke detector goes off unnecessarily:

Do not silence the smoke detector by taking it down or taking the battery out. Air the area/room in which the alarm is located. If you repeatedly get unnecessary alerts, move the alarm to a better location. Smoke detectors with a pause button are also available.

where to install smoke detector in ceiling

Purchasing, installing, maintaining and testing a smoke detector and responsibility for smoke detectors

Old type detectors

Old type smoke detectors are battery powered. They must be purchased, replaced, installed, tested and maintained by the resident/occupant of the flat or house. When selecting a smoke detector, think about the room in which you will place it and how you can maintain and test it.

TEST the smoke detector every month by pressing its test button.

Some smoke detector types are easy to test and maintain as they have a battery case attached to the wall. Purchasing a detector of this type is worth considering, especially for the homes of older people. In addition, some battery cases have a pause button for ‘false’ alarms: the smoke detector can be switched off for about 10 minutes if necessary. After the pause, the smoke detector automatically starts operating normally. 

Mains-powered detectors

The real estate or housing company is usually responsible for maintaining smoke detectors connected to the mains. These detectors are installed in the construction phase and connected to the building's electrical wiring. The places of the detectors are decided in the building's wiring design, and the detectors are installed by a professional electrician. A mains-powered smoke detector has a backup battery in case of a power outage.

The resident or occupant is responsible for testing a mains-powered smoke detector regularly. In a limited liability housing company, the housing company has the primary duty to change the backup battery of a mains-powered smoke detector, rather than the resident. As there are many different models of mains-powered smoke detectors and their technical solutions vary, changing their batteries and the party responsible for this task should be discussed at the housing company’s meeting. If nothing else, the residents should be given instructions for changing the batteries.

A good practice in property maintenance would be that the housing company looks after regularly changing the batteries in mains-powered smoke detectors. For example, this would help to avoid cases where the smoke detector goes off in the middle of the night to indicate that the battery has run out. Depending on the smoke detector model, the representative of the maintenance company may not have the skills or rights to replace the battery, either, and this task should be carried out by a professional electrician.

To prevent false alarms, you should check if the alarm has a so-called pause button. Some manufacturers' models can be silenced, for example while cooking. Similarly, it may be possible to silence the low battery warning for the night.

It is particularly important to give the residents clear instructions on what to do with a mains-powered smoke detector in different situations. Find out about these and other safety practices as soon as you move into your flat!

Other detectors & alarms

Carbon monoxide alarm

Carbon monoxide is a gas that has no smell, taste or colour and that is slightly lighter than air, highly flammable and toxic. It cannot be detected by human senses. Carbon monoxide is formed as a result of incomplete combustion, for example when burning wood, LPG, petrol or oil. Its sources include fireplaces, gas appliances and vehicle exhaust fumes. 

People used to say that heat will escape if you air the room; this is an old-fashioned idea and not really true

The carbon monoxide alarm only warns you of carbon monoxide in the room. It does not give a warning of smoke or other gases. This is why you must always have a smoke detector and, if necessary, also a gas detector. Having a carbon monoxide alarm is not compulsory. You should get one if you have fireplaces or gas appliances in your home.

Where should a carbon monoxide alarm be placed?

  • a carbon monoxide alarm should be installed in the room where fuel is used (such as a fireplace, gas cooker or other stove)
  • you must be able to hear the sound of the carbon monoxide alarm in the rooms where people sleep or spend time
  • an alarm installed on the ceiling should be placed at least 300 mm away from all walls
  • if you have a combined smoke detector and carbon monoxide alarm, it should be fitted onto the ceiling
  • a wall-mounted alarm should be placed at least 15 cm away from the ceiling, as air may become trapped in the corner formed by the wall and the ceiling. However, the alarm should be located higher than all doors and windows.
  • always check the requirements in the installation instructions that come with the carbon monoxide alarm.

How do you prevent dangerous levels of carbon monoxide?

  1. do not close the flue or extractor fan of the fireplace too early
  2. always use and maintain gas appliances following the operating instructions
  3. make sure that the installations and connections are secure and have been made correctly
  4. ensure sufficient ventilation
  5. keep an eye on the condition of the fireplace and flue continuously
  6. have the chimney swept once a year
  7. remember that exhaust fumes and coal barbecues produce large volumes of carbon monoxide

Gas detector

Liquefied petroleum gas, or LPG, is a highly flammable gas that contains propane/butane. If it ignites, it causes an explosive, powerful fire. The gas detector warns you of even a small leak.

Always get a gas detector if you have gas appliances in your home. You should also have a gas detector in your holiday house, caravan, campervan and boat. Refer to the operating instructions and the manufacturer to check that the gas detector is suitable for your uses.

Fixed LPG installations may only be made by an approved installation company – do not try and make your own installations!

As LPG is heavier than air, the gas detector should be installed near the floor level. The gas detector is usually connected to either 12V or 230V mains power as its power consumption is quite high for batteries.

Facts about LPG

  1. LPG is safe to use when it is handled and stored according to regulations
  2. read and follow the instructions for use
  3. make sure your appliances are designed to work together
  4. check regularly that the appliances, accessories and connections are in order
  5. keep the appliances and burners clean
  6. close the cylinder valve when you no longer use gas appliances 
  7. make sure you have effective ventilation and remember that...
  8. LPG is heavier than air and sinks to the floor level or below it
  9. causes you to go unconscious if you are asleep

Read more:

Ministry of the Interior Decree on the Placement and Maintenance of Smoke Detectors (in Finnish)
Government Decree on the Technical Properties of Smoke Detectors (in Finnish)
Smoke alarm requirements, placement and maintenance
Homes have too few working smoke detectors (In Finnish)
Carbon monoxide alarms