late last week I ordered a heating system for my brewing. it consists of a ferm wrap, a thermowell cap, and a two stage Ronco temperature control. now I know I have to tape the wrap to the carboy and plug it into the controller. but when I go to connect the controller's temp sensor to the thermowell I run into a bit of a problem. the sensor will not fit securly into the thermowell. the sensor is to thick. what am I missing?