Do the batteries need to be replaced?
The gauge is not working: You may need to replace the batteries.
To replace the batteries:
- To remove back cover: Grasp back cover and pull away from the unit. Set the cover aside.
- Use a Phillips screwdriver to loosen the screw holding the battery compartment cover plate in place.
- Replace three AAA batteries in the battery compartment, put the cover plate in place, and secure with the screw.