Cookworks oven

I have a Cookworks (Sovereign?) built in electric fan oven/grill It is a pretty basic model – temperature and minute timer knobs, and LED clock. When power is turned on at the wall switch, the clock comes on and the indicator light flickers. The fan oven does not come on. It is situated in a flat I own, and the instruction leaflet does not help. Could it be something to do with the position of the timer knob, (its only a minute countdown timer) or the knob which turns on either the grill or oven, or would it be a fault that needs looking at. It’s still within the 1 yr guarantee, but the shop I bought it from can’t seem to supply me with the phone number of who I should ring to get someone round to look at it. Any ideas???