Which action should be avoided while maintaining smoke detectors?

Using a hairdryer to clean smoke detectors is not advisable because it can generate high air pressure and potentially damage the sensitive components within the smoke detector. Smoke detectors are designed to detect smoke particles, and blowing air from a hairdryer could disrupt the internal mechanisms, leading to false readings or operational issues. Maintaining a smoke detector should involve careful cleaning methods, typically including using a vacuum with a brush attachment or a soft cloth, to ensure the unit remains effective and operational without introducing the risk of damage from high-velocity air.

Regularly testing the unit, replacing batteries annually, and keeping the area dust-free are all important practices that help ensure smoke detectors function correctly and safely protect occupants from fire hazards.