CHESTERFIELD • Monarch Fire Protection District firefighters are hoping to use a family's close call with carbon monoxide poisoning as a reminder about the importance of detectors.

Firefighters were called to the family's home in the 14000 block of Cross Trails Drive in Chesterfield at about 3 a.m. Saturday after a carbon monoxide detector went off. Two boys, ages 8 and 11, and their parents were in the home.

Tests showed carbon monoxide levels were at a level that can produce flu-like symptoms such as headaches, sore eyes and a runny nose, according to Fire Marshal Roger Herin.

Firefighters discovered a down-drafting condition within the heating equipment in the house, which made the products of combustion flow back into the house, Herin said in a statement.

"It is not known how long this condition existed, but had it continued it would have built up significantly in a short amount of time, endangering the occupants' lives," he said in the statement. "This is a situation that could have been disastrous had the occupants not had a working carbon monoxide detector."

Herin said carbon monoxide detectors that are more than five years old should be replaced and batteries should always be checked.