December may be the month when chimneys are more top-of-mind than usual—especially for those waiting for Santa— but CMC Energy Services professionals understand year-round the importance of the chimney to a home and the necessity for its safe upkeep.

According to Program Supervisor Steven Cobb, who oversees CMC’s comprehensive support of County Weatherization Assistance Programs in Pennsylvania and New Jersey, chimney blockage or misalignment can lead to exhaust gasses backing up and entering the home through the draft hood.
“This is a very dangerous situation, so our technicians do a variety of tests to ensure that this is not happening and occupants are safe,” Cobb says. “There are several ways to test for this problem, but some are expensive and complicated, and others, like using smoke from a smolder wick, do a good job of showing leaking gasses, but leave the house smelling bad.”

Cobb and his team use mirrors to detect spillage. According to Cobb, by holding the mirror at the edge of the draft hood, a technician can visually confirm whether or not exhaust is spilling out of the system by identifying any condensation on the glass surface.“If condensation is observed, they know there is a problem and more extensive testing can be done to locate the problem so the source of the issue can be fixed,” he adds.

Because of Cobb, now not only are all CMC field staff across the company trained on detecting spillage, they are putting to use in the field what they’ve learned with CMC-branded spillage mirrors.

“The initial feedback on this effort has been very positive from the managers and the field staff themselves.” For more information, contact Cobb at

Back to Top
Skip to content