Replacing the manufacturer thermometer with a River Country RCT-34 (3" dial, 4" stem, 1/2 npt"). After what felt like an half hour of drilling, I was finally able to screw in the thermometer. It threaded fine but the nut (npt??) is still on the outside of the door. Is this how it' supposed to be or is the dial supposed to be flush with the door? Thanks!