Make sure that there is really no source of fire. Switch off the signal tone, depending on the type, press the mute button or remove the battery. Make absolutely sure to put the smoke detector back into operation afterwards! Locate the source of the interference and remove it, then test the smoke detector for proper operation.
Remove the smoke detector from the base and use a vacuum cleaner to clean the slots on the side of the smoke detector and free it from dirt, dust or animals.
If no source of interference can be located and the detector repeatedly triggers a false alarm, use the "Submit Inquiry" function below this post.