This is where the "exchange" happens: the hardness minerals are swapped for sodium. The water that exits the tank and flows into your home is now "soft" and free of scale-causing minerals.
This comprehensive guide covers everything you need to know about the 40278 water softener, including its core specifications, routine maintenance, common error codes, and how to find replacement parts. Technical Specifications: The Kenmore 40278 at a Glance
: Specifically designed to maintain normal water pressure throughout the home, preventing the "pressure drop" common with smaller, standard valves.
The , formally indexed by its model code 420 (Sears model number 625.384200 ), is a heavy-duty, single-tank demand-initiated water treatment system. Engineered primarily for mid-to-large-sized families experiencing severe hard water, this unit balances a high-flow plumbing footprint with predictive salt savings.
The small 24V motor that turns the internal valve gears.
: Includes an indicator that alerts you when salt levels are low, along with an internal light to assist with maintenance in dimly lit basements or utility rooms. Installation and Maintenance
"It's just a switch," Elias said, looking at the tiny part online.
The 40278 functions using a single-tank "cabinet" design, where the salt storage well surrounds the mineral resin tank.
Once the resin beads are coated in calcium and magnesium, the system draws a concentrated salt brine solution from the storage tank. The heavy concentration of sodium forces the hardness minerals off the resin beads.
: A standard 110V outlet is required nearby for the control board.
When you see on a water softener, it generally does not refer to the entire softener system itself. Instead, it is an engineering part number associated with components of classic Fleck control valves .
If you are looking for a specific part for this model, these are the most frequently replaced components: Seal and Spacer Kit (Part #7185487)