Because a downdraft system pulls air sideways and down rather than up through an overhead canopy, grease and cooking residue accumulate along a different path than they would with a hood — and that path is easy to forget about since most of it is hidden below the cooktop surface.
Why Grease Buildup Here Is Dangerous
Grease captured in the intake screen and duct run sits close to an active heat source on every cooktop, whether gas or induction. A heavy buildup of grease inside ducting that runs near enough to a heat-generating burner is a genuine ignition risk, not just an airflow inconvenience.
Warning Signs Worth Taking Seriously
A noticeably weaker draw at the vent opening, a burning or acrid smell during high-heat cooking, or visible grease pooling around the intake grille are all signs the system needs attention before it becomes a hazard rather than just a performance issue.
What to Do If You Smell Burning
Turn off the cooktop and the vent fan immediately, and don’t run either again until the ducting and blower housing have been inspected.
Prevention Is Straightforward
Regular grease-screen cleaning and a periodic full duct inspection are the two habits that keep this risk in check. Visit our JennAir cooktop repair page if you’re overdue.