DuraWater Fleck 5600SXT 48K
A standard Fleck 5600SXT softener for a typical family, best for buyers who already trust the Fleck valve and the seller.
Amazon $825$825
2.8/5
A certified 40,000 grain demand softener for well or city water, but the price is hard to justify against similar models.
- 40,000 grainsCapacity
- 7.7 gpmService flow
- YesNSF/ANSI 44
Check price at Amazon$822.77
Price checked November 1, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Certified by NSF for capacity and salt efficiency
- Built-in sediment screen helps on well water
- Learns household water use and regenerates only when needed
Cons
- Priced well above comparable 40,000 grain demand softeners
- Service flow under 8 gpm for a unit sized for up to five people
The Kenmore 350 and 420 family
Every Kenmore 350 and 420 model we rank, smallest first. Ratings compare each against its own size.
| Model | Capacity | Rating | Price |
|---|---|---|---|
| Kenmore 350 | 32,000 grains | 3.1/5 | $621.29 |
| Kenmore 420 (this one) | 40,000 grains | 2.8/5 | $822.77 |
How it scores
The rating comes from 5 measured or published factors, each scored 0-100 against fixed reference points for its size. How we rank explains each one.
Specifications
| Model number | 625.384200 |
|---|---|
| Capacity | |
| Rated capacity | 40,000 grains |
| Service flow | 7.7 gpm |
| Control | |
| Valve | Kenmore demand valve |
| Regenerates on demand | Yes |
| App or remote monitoring | No |
| Certification and warranty | |
| NSF/ANSI 44 | Yes |
| Valve warranty | 3 years |
| Tank warranty | 10 years |
Alternatives in this size
Tier1 Essential 48,000 Grain
A low cost 48,000 grain softener for a typical family on city water, for buyers who put price ahead of warranty and published ratings.
Amazon $599$599
SpringWell SS4
A mid size softener for four to six bathrooms, for buyers who want a long warranty and will pay well above budget brands for it.
SpringWell $1,680$1,680
Compare
Compare the Kenmore 420 with any other water softener →
More from Kenmore: every Kenmore product ranked.