If your SmartLine or ProLine controller's LCD is displaying BAD OSC, this indicates a panel failure as a result of a failed Quartz crystal mounted between the board and the microprocessor.
The panel will simply need to be replaced. Return the panel to your local distributor for a warranty replacement or submit a warranty request to us at support@weathermatic.com. Please provide the date code from the back left-hand side of the panel when opened away from the controller's cabinet. See the image below.