Adjusting boiler thermostat rotary control

I would like to adjust the position of the rotary control on my boiler, quite a small amount say 90 degrees.

Zigbee would be my favourite and I thought of some adaptation of say a blnid motor.

Regulations in UK do not permit removal of the boiler cover by the uncertified so it would need to be some sort of contact that could be easily removed for serviing.

Any thoughts gratefully received.