After sweeping a flue, what should be used to ensure there are no obstructions or blockages?

The use of a mirror or flashlight is an effective method to ensure that there are no obstructions or blockages in a flue after sweeping. A flashlight provides a strong beam of light that can illuminate the interior of the flue, allowing the sweep to visually inspect for any remaining debris, creosote buildup, or other potential blockages. A mirror can also be useful in navigating corners or angles where the flashlight may not provide a direct view; it helps in reflecting light into hard-to-see areas, ensuring a thorough inspection.

Effective chimney maintenance requires that all aspects of the flue are checked after sweeping to ensure safe operation. Using a mirror or flashlight allows for a more comprehensive evaluation compared to other methods. While a camera could offer a visual record, it might not provide the immediate insight needed during an inspection. Similarly, while a candle or incense might give indications of airflow, these are not reliable tools for checking physical blockages. Finally, while rods or brushes are essential tools for the sweeping process itself, they do not serve the purpose of inspection post-sweeping.