Diplomat gas oven model 600GA keeps shutting off!?

Can anyone explain why my Diplomat gas oven model 600GA APP0153 with model #050502088 seriel # 41155630 keeps switching itself off! It's almost like there is a timer on it and given I inherited this oven which I have no instructions for, have no idea if this is the problem?
After 5 min or so, the green LED displays itself again and will spark & ignite without any problem then after 10 min, everything switches off again. Have since reverted to the micro for my tea. Can anyone help?