After some dealers reported corrosion in some Pulse furnace heat exchangers in units installed before 1990, Lennox said in April that it would pay its dealers to inspect the furnaces. The company also is providing free carbon monoxide detectors as part of the program.
Carbon monoxide is an odorless, colorless gas that can cause sickness or death.
The Dallas-based Lennox manufactures furnaces in Marshalltown, where the company was founded in 1895.