Chimney Safety Institute of America (CSIA) Certification Practice Test

Which type of brush is best for removing glaze in the flue?

1. Flat wire brush

2. Chain brush

3. Rotary brush

4. Round brush

The correct answer is: Chain brush

The chain brush is particularly effective for removing glaze in the flue because its design features multiple chains or flexible wire sections that can adapt to the contours of the flue while providing a scrubbing action. This flexibility enables the brush to penetrate and dislodge hardened deposits, such as glaze, which can be particularly stubborn. The chain links help in agitating and scraping off these deposits without risking damage to the flue liner, thus ensuring a thorough cleaning process. In contrast, other brushes may not be as effective. A flat wire brush is generally more suited for flat surfaces and may not reach into the flue's varying shapes effectively. A rotary brush, while powerful, could potentially cause damage or ineffective cleaning in tighter sections of the flue. A round brush may be useful for general cleaning but may lack the aggressive scrubbing action necessary to remove tough, baked-on glaze. Therefore, the chain brush is the preferred tool for this specific cleaning task.