Stoves 720G Oven & Grill - The Grill wont switch off?

My Stoves grill wont switch off, when the dial is turned to off position, the grill drops its output to half the lights start flickering and there is clicking noise heard - I suspect the Grill Solenoid
If the grill door is closed the grill cuts out like it is supposed to. Shutting off cooker at the mains shuts off the grill and it remains off until activated again.
The grill does start up correctly and work normally until its time to shut it off ?