Hi, hopefully some one can help please . We have a dial esi ESRTD2 thermostat and the dial wouldn’t turn past one. We have brought a new one exact same model new batteries in it ect and just replaced it. The problem is it won’t turn the heating on. Do we need to take the back plate off and do some rewiring? Or check something else? Total novice just thinking we could take off the old thermostat and replace with new and it would work