There is a black oily soot building up on my cooking grids and more importantly on my food, what could cause this?
The black buildup is a sign that your venturi tubes on your burner may have a blockage, and will not allow enough gas and air flow to reach the burners. Alternately, your barbecue grill may need a thorough cleaning. To correct this, follow these simple steps:
When cool, remove your burner and inspect the ports. If the ports are blocked, clean with a soft bristle brush. Alternately you can clear the debris out by poking blocked holes with a paper clip (or another tool small enough – never drill or file portholes, enlarging them will damage your burner).
Next, clean out the burner venturi tubes. Use a venturi brush or pipe cleaner and push it through the entire tube while turning. Pull out the brush and examine for any debris. Be aware that spiders are attracted to thesmell of gas, and may have taken residence in your venturi tubes. To prevent this, make sure the spider guards are protecting the air intake holes at all times.
There also may be a buildup of grease burning on the bottom of the oven. To correct this, remove the cooking grids and the Flav-R-Wave™ heat medium. Use a stainless steel barbecue grill brush and scrub the bottom of the oven to loosen debris. For a thorough cleaning, use an industrial vacuum cleaner to remove any ash and debris.