Find the Oil Control unit (usually bolted to the side of the cooker under a Black cover), which lifts vertically off, or if the aga is built into kitchen cupboards, you'll find it in the bottom of one of the cupboards either side of the cooker. once you have found the Control Valve, you will see that at the front on the top corner is a small lever sticking out the side, to extinguish the burner, lift the silver lever with your finger until you hear a "Click", the burner will take about 10mins to go out, and the Cooker will take about 10 weeks to cool down (only joking!). However Do Not attempt to relight the burner while the Cooker is still warm under any circumstances!!!
www.elanar.co.uk, September 2009