On my Cannon, I press the "Manual" button.
http://www.gotogasdocs.co.uk/f/m/Cannon/Cookers/Harmony%20Mk2%20IUM.pdf
Page 7.
Note the clock also needs to be set properly!
You should be able to find a manual for your own cooker easily enough. just do a Google search for "cannon MODEL manual" (replacing "MODEL" with your own info, naturally.
Surprised you didn't do this anyway.
acp, July 2017
