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Carbon monoxide and heat detectors are not substitutes for smoke detectors

carbon monoxide (CO) detector is a device similar to a smoke detector intended to warn of carbon monoxide gas.  However, as it does not warn against smoke or other combustion gases, a CO detector is not a substitute for a mandatory smoke detector. Carbon monoxide is formed as a result of incomplete combustion, for example in fireplaces and gas-powered appliances. The authorities recommend installing a CO detector in rooms with, for example, a fireplace, gas stove or gas refrigerator.

A detector that only responds to heat and increases in temperature is also not a substitute a mandatory smoke detector. A heat detector can be used as an additional alarm device in spaces where a smoke detector is not suitable, such as in the kitchen, where cooking may cause false alarms from a smoke detector. There is also separate safety equipment for preventing stove fires, stove guards.

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 Tukes