SootGuard oil burner back pressure
SCUD PRODUCTS oil burner fuse
The SootGuard from American Spirit Unlimited, LLC is a patented, "hi-tech" oil burner fuse engineered to open at the advent of back pressure. It installs simply into the inspection plate of an oil-fired boiler or warm air furnace. Two leads connect to the TT terminals at the burner control. It only takes minutes to install.

Should chimney blockage or unit plugging cause back pressure to increase to a positive (+) .04 draft, the fuse in the SootGuard will open. The open fuse translates to an open circuit at TT causing immediate burner shut down.
sootguard
The fuse element opens as hot gasses enter the device under pressure. Intake and exhaust port dimensions have been scientifically designed to respond to a specific positive (+) .04 draft. The patented SootGuard oil burner fuse has been tested extensively in the field and is a proven, sure fire solution to problems caused by high back pressure.