FishTank4CT,
Commercial products are not discussed here on this consumer leisure marine support forum. If you continue to have problems or questions on that device, please contact official support of your local Furuno distributor.
But a quick answer to your question regarding the changing for the CSH8LMK2's temperature from Celsius over to Fahrenheit. The CSH8LMK2 can only display the temperature in Celsius format only. It does not allow for the ability to covert over to Fahrenheit in it's software...
- Deep Blue