Smeg Hob goes to sleep ?

We have a brand new Smeg Hob (SmegSE2664TC2) - absolutely lovely and works like a dream - however, if i don;t use it for a whole day, it goes into some sort of deep hibernation and we have to turn off the power supply to "reset" it.

Smeg are trying to tell me it is the wiring, but both the electrician and an independent engineer are telling me that is rubbish - if it were the wiring the hob or circuit breaker would cut out when it is being used - not switch itself off when it hasn't been used for a day.

Anyone heard of this before ?