Plexvent and Ultravent HTPV were recalled in February 1998. Changes were made to this recall in 2009.
Plexvent owners Ultravent owners
Valid claims initiated after October 1, 2009 will receive:
A rebate up to $400 toward either an HTPV replacement system, or a new, high-efficiency furnace from Goodman that does not require HTPV. A rebate up to $250 toward either an HTPV replacement system, or a new, high-efficiency furnace from Goodman that does not require HTPV.
In 2016, I came across this system that was still in use but had not been serviced since the recall was initiated way back in 1998. The recall was widely publicized to heating service personnel and home inspectors through continuing education programs. The recall measures were fully funded by the manufacturers so any competent service technician would have notified the homeowner immediately. If you have a system like this here are a few photos to help you identify it.
Link to Consumer Product Safety Commission announcement for this recall