There are several indicators that a chimney needs to be cleaned. The apparent sign is creosote buildup, a black, gooey substance along the chimney walls. Other warning indications include a strong, disagreeable smell coming from the fireplace, a lot of smoke or soot being created while using the fireplace and reduced draught or airflow. Regular chimney inspections and cleanings are necessary for a fireplace system to be both safe and efficient. To know in detail visit the blog post about the signs that the chimney needs cleaning.