Your apartment is fitted with mains powered smoke detectors, with battery back-up to ensure safe operation in the event of a power failure. The operation of these alarms should be checked on a regular basis. A battery that requires replacement will emit a regular 'chirruping' sound.
In addition to the smoke detectors visible in your entrance hallway and bedroom(s), there are additional smoke detectors located in the ceiling voids that are connected to the FCUs. To access these smoke detectors please see the section on Heating.