Are you replacing an existing heater? Please enter the Serial Number, Model Number and contact information below. For Flanged heaters these can be found on the dry flat side of the flange between the bolt holes, or on the label inside the terminal enclosure. For Screw Plug heaters they can be found on one of the flats of the hex plate or on the label inside the terminal enclosure. If you need help refer to the Warren Model Number Description.