If your 40278 water softener is full, it means that the resin tank is saturated with calcium and magnesium ions and can no longer effectively soften the water. This can happen for several reasons:

If the water level is just a few inches high, that is normal.

Searching for the "40278 water softener full"? This in-depth guide covers everything from specifications and installation to troubleshooting common error codes. Discover if this 48,000-grain unit is the right solution for your hard water problems.

Turn off the water supply to the softener or put it on "Bypass."

If your water softener screen is flashing "40278" or showing a "Full" error, you are likely dealing with an overflow or a sensor malfunction. This specific code often appears on models manufactured by brands like Kenmore, Whirlpool, or EcoPure, which share a common internal design.