The answer to 'when to replace humidifier' is that you should typically replace your home humidifier every 1-2 years, or when it starts to show signs of wear and tear. Humidifiers are an important part of maintaining indoor air quality, but they require regular maintenance and replacement to function properly.
Over time, the internal components of a humidifier can become clogged with mineral deposits, mold, and other contaminants. This can reduce the unit's efficiency and even lead to the release of unhealthy particles into the air. Replacing the humidifier on a regular schedule helps ensure it continues to operate safely and effectively.