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How this review was put together: from Kenmore Water Solutions’ product page, the Kenmore 350 owner’s manual (model 625.383500) and NSF International’s public certification listing (links in “Sources” at the end). We have not tested this softener ourselves. How we review. Last checked 28 October 2026.
The short version
The Kenmore 350 is a compact, all-in-one (cabinet-style) salt-based water softener aimed at homes of 1–4 people. It is sold as a “32,000-grain” softener, and its NSF/ANSI 44 certification confirms the capacity: 32,100 grains at the highest salt dose. It is also efficiency rated, which means it met NSF’s minimum standard for salt and water use at its lowest salt setting.
It regenerates on demand: it measures water use and only regenerates when the resin needs it, not on a fixed timer. The trade-offs are a modest certified flow rate of 7.2 gallons per minute, a 1-year parts-and-labor warranty, and a design aimed at smaller households.
See the Kenmore 350 on Amazon (paid link)
Who it suits, and who should look elsewhere
A good fit if you
- Have 1–4 people and moderate hardness (see the sizing example below).
- Have limited space. The salt and resin are in one cabinet, 48 in tall, 15 in wide and 20.5 in deep.
- Want a softener whose capacity, flow and efficiency are confirmed by a third-party certification.
Probably not the right pick if you
- Have a large household or several bathrooms in use at once. Look at higher-flow two-tank systems such as the Fleck 5600SXT 48k.
- Have ferric (red-water) iron, bacterial iron, or colloidal iron. The manual says it won’t remove these.
- Want drinking water treatment. A softener swaps hardness minerals for sodium. It doesn’t filter out lead, PFAS or chlorine, so pair it with an RO system at the kitchen tap if you need those.
Key specifications
From the Kenmore 350 owner’s manual (model 625.383500) and NSF’s listing.
| Spec | Kenmore 350 | What it means in practice |
|---|---|---|
| Type | Cabinet (all-in-one) salt-based softener, demand-initiated regeneration | Regenerates based on metered use, not a timer. |
| Rated capacity | 12,600 grains at 2.5 lb salt; 26,900 at 7.9 lb; 32,100 at 13.3 lb | Lower salt doses are more efficient but regenerate more often. |
| Efficiency | 5,040 grains per lb of salt at the lowest dose | NSF/ANSI 44 efficiency rating requires at least 3,350 grains per lb. |
| Service flow rate | 7.2 gpm (15 psi pressure drop) | Fine for a small home; it may limit flow if several showers and appliances run together. |
| Resin | 0.83 cubic feet | |
| Max hardness | 90 grains per gallon | |
| Max clear-water iron | 8 ppm | Add 5 grains to the hardness setting per 1 ppm of clear-water iron, per the manual. |
| Water pressure / temperature | 20–125 psi; 40–120°F | |
| Water supply needed | At least 3 gpm | Check your well pump if you aren’t on city water. |
| Drain flow | 2.0 gpm | You need a floor drain, standpipe or laundry tub nearby. |
| Water per regeneration | 32.4 gallons at the highest salt dose | |
| Power | 24 V DC plug-in adapter (needs a 120 V outlet) | |
| Size | 48 in high × 15 in wide × 20.5 in deep; 1 in NPT connections (3/4 in high-flow valve) | |
| Warranty | 1 year parts and labor; 3 years electronics; 10 years tank | From the manual; check the current terms when you buy. |
Other features from the manual: a bypass valve, a low-salt warning light, an optional “Salt Efficiency” mode (at least 4,000 grains per lb of salt, with more frequent regenerations), an optional “Clean” cycle for iron or sediment, and a setting to force a regeneration after a set number of days (up to 15) even if water use is low. The softener is made by Water Channel Partners under license from Kenmore.
Certification: what was verified
Status: certified. NSF International lists model 625.383500 under NSF/ANSI 44 (residential cation exchange water softeners), for hardness reduction and as efficiency rated, with a service flow of 7.2 gpm. It is also certified under NSF/ANSI 372 (low lead content). NSF listing.
“Efficiency rated” under NSF/ANSI 44 means the softener delivers at least 3,350 grains of hardness removal per pound of salt and uses no more than 5 gallons of water per 1,000 grains removed, at its lowest salt setting. The Kenmore manual lists 5,040 grains per lb and 1.7 gallons per 1,000 grains.
The manual also says the system is WQA-certified to CSA B483.1. We didn’t find that in WQA’s directory, so we’re relying on the NSF listing.
How to size it: a worked example
The EPA’s WaterSense program estimates the average American uses about 82 gallons of water a day at home. Take a household of 4 with 10 grains-per-gallon hardness:
- 4 people × 82 gallons = about 330 gallons a day
- 330 gallons × 10 grains = about 3,300 grains of hardness a day
- At the lowest salt dose (12,600 grains) that’s a regeneration roughly every 3–4 days. At the middle dose (26,900 grains), roughly every 8 days.
That is comfortable. At 25 gpg and 4 people, the daily load climbs to about 8,200 grains, and the 350 would regenerate every few days even at its top dose. That’s when a larger softener starts to make more sense. Your own water test and meter reading are better than our estimates. See why you might still have hard water with a softener if the numbers look off.
What we like and what to weigh up
Strengths
- Independently certified capacity, flow and efficiency (NSF/ANSI 44).
- Efficient at its lowest salt setting: well above NSF’s efficiency minimum.
- Compact all-in-one cabinet with demand-initiated regeneration.
- Reduces moderate clear-water iron (up to 8 ppm, per the manual).
Drawbacks
- 7.2 gpm flow is modest for larger homes.
- Short parts-and-labor warranty (1 year), though the tank is covered for 10.
- Adds sodium to the water, like any salt-based softener. See do water softeners add sodium to drinking water?
- Needs a drain and an outlet close by.
Maintenance and running costs
- Salt: the main running cost. More salt per regeneration gives more capacity but lower efficiency (see the capacity table).
- Water: about 1.7 gallons per 1,000 grains removed at the lowest dose, and 32.4 gallons per regeneration at the highest.
- Upkeep: top up salt when the low-salt light comes on. If your water has iron or sediment, the manual suggests turning on the “Clean” cycle (an extra backwash before each regeneration). Otherwise leave it off to save water.
Salt and water prices vary a lot by area, so we don’t quote costs. For the bigger picture, see are water softeners worth the expense?
Alternatives worth comparing
- Larger homes or higher flow: the Fleck 5600SXT 48k.
- Comparing them all: see our best water softeners guide.
Common questions
Is softened water OK to drink?
For most people, yes, but it does contain added sodium. See is it healthy to drink water softener water? and how to remove sodium from softened water.
Does it remove iron?
Moderate clear-water (ferrous) iron, up to 8 ppm, per the manual. It won’t remove ferric, bacterial or colloidal iron.
Can I install it myself?
Kenmore’s manual covers DIY installation, but it also notes local plumbing codes apply, and some areas require a licensed plumber.
Check current availability of the Kenmore 350 on Amazon (paid link)
