What would cause flames to come off the barbecue around the dial?
It sounds like there is a blockage preventing the gas from flowing evenly from the control knobs to the burner. Although the cause could be a defective valve, the most likely culprits are spiders. They climb inside the two venturi tubes that transmit gas or propane to the burner. A venturi tube is a lovely home for a spider because it’s a dark, enclosed space. But when the spider spins its silk and plugs the hole to protect itself, you’re in for a potential eyebrow scorching or worse.
A good solution is a venturi tube cleaner. It’s basically an 18-inch toothbrush with a flexible wire head. Before you start your grill for the season, insert the brush into each venturi tube and twist it around. You may have to disconnect the burner to get to the venturi tubes, depending on the make and model of your barbecue. It’s probably a good idea to clear out the venturi tubes regularly throughout the summer, particularly at the cottage, where spiders abound. And while you’re at it, check the status of your burner. A season’s worth of delicious marinade, sauce, and fat drippings can clog the holes in it, preventing the gas from flowing properly. This can also result in a backfire, and an accumulation of oily gunk in the drip pan can set off a grease fire. Unclogging burner holes is simple: Just rub them down with a steel wire brush on a regular basis.