Direct answer: The 2026 Watts dealer catalog lists five residential softener families. The W100-valve CK10SM models are the basic metered softeners: M3011-CK10SM (30,000 grains), M3013-CK10SM (45,000) and M3015-CK10SM (60,000). The M3011-W100SM-CR-CMP puts carbon and resin in one tank. The Locksmith CLS-100 and CLS-125 use Watts’ own composite valve, from 30,000 to 120,000 grains. Locksmith CLSTA-100 and W100T twins alternate two tanks for uninterrupted soft water, up to 210,000 grains. OneFlow is Watts’ salt-free scale-prevention line, not a softener.
Publisher boundary: Water System Guide is an independent research publisher, not a Watts dealer. This page uses the Watts Water Quality dealer catalog C-WQ-Dealer 2604 (April 2026) and the Watts water conditioner operating manual with the WM100SM valve (FORM 0500-200, PDF created 2006), reviewed October 15, 2026. Capacities are Watts’ maximum figures; the catalog notes they “are based on resin manufacturer’s data.” No prices are published.
The families at a glance
| Family | Valve | Capacity range (max) | Pipe | Best fit per Watts’ description |
|---|---|---|---|---|
| CK10SM | W100 metered | 30,000–60,000 | 1” | Standard household softening |
| Dual-media W100SM-CR-CMP | W100 (“CK-10 metered”) | 30,000 | 1” | Chlorine, taste and odor plus hardness in one tank |
| Locksmith CLS-100 | Locksmith composite, metered demand | 30,000–90,000 | 1” | Watts’ own controller with operating history |
| Locksmith CLS-125 | Locksmith composite | 30,000–120,000 | 1.25”/1.5” | Larger homes and higher flow |
| Twin alternating (CLSTA-100, W100T) | Locksmith or W100T | 30,000–210,000 | 1” to 1.25”x1.5” | Soft water “24/7, without interruption” |
W100 CK10SM softeners
The catalog calls these “Water Softeners with Watts W100 Valves” and describes them as “complete systems including: W100 high flow, metered valve; standard mineral tank; black brine tank; float valve to prevent brine overflow; by-pass valve.” It explains that metered valves give “greater efficiency and reduced salt usage, because regeneration of the softener resin is based on water consumption” (dealer catalog, PDF page 20).
| Model | Ordering code | Capacity | Tank | Resin | Brine tank / salt | Service gpm | Backwash gpm |
|---|---|---|---|---|---|---|---|
| M3011-CK10SM | 68105249 | 30,000 | 9x48 | 1 cu ft | 18x36 / 350 lb | 9–12 | 2.2 |
| M3013-CK10SM | 68105297 | 45,000 | 10x54 | 1.5 cu ft | 18x36 / 350 lb | 12–16 | 2.7 |
| M3015-CK10SM | 68105343 | 60,000 | 12x52 | 2 cu ft | 18x36 / 350 lb | 15–20 | 3.5 |
Service flow is given at a 15–25 psi pressure drop. The operating manual for the same valve family lists minimum programmed capacities of 20,000, 30,000 and 40,000 grains for these resin volumes, at 6, 9 and 12 lb of salt (WM100SM manual, PDF page 4). Our Watts regeneration guide explains the settings.
Dual-media M3011-W100SM-CR-CMP
This model is “water softener and carbon filter in one compact design.” Its listed benefits are to reduce hardness, chlorine, taste, odors and iron (the catalog marks iron with “pre-treatment may be required”). The catalog’s design notes say “carbon and resin are in separate chambers,” there is “no media migration,” and “carbon can be replaced without replacing the resin.” It is “assembled and tested in USA” (dealer catalog, PDF page 18).
| Model | Ordering code | Capacity | Tank | Resin | Carbon | Brine tank / salt | Service gpm | Backwash gpm |
|---|---|---|---|---|---|---|---|---|
| M3011-W100SM-CR-CMP | 68110658 | 30,000 | 10x54 | 1 cu ft | 0.5 cu ft | 18x36 / 350 lb | 12–16 | 2.7 |
Compared with the M3011-CK10SM, it has the same 30,000-grain maximum and 1 cubic foot of resin, but in a larger 10x54 tank to make room for the carbon chamber. Watts also lists a Locksmith-valve dual-media version, the M3011-L10SM-CR-CMP.
Locksmith CLS simplex softeners
Locksmith systems are softeners “with Watts Exclusive Valve Controller.” The catalog lists a “glass fiber reinforced composite control valve,” “fully automatic metered demand control,” “sophisticated digital electronic controls that store accessible operating history,” “fully adjustable regeneration cycles” and “high-capacity A4000 resin certified for lead-free compliance” (dealer catalog, PDF page 19).
| Model | Capacity | Pipe | Tank | Resin | Brine tank / salt | Service gpm | Backwash gpm |
|---|---|---|---|---|---|---|---|
| M3011-L10SM | 30,000 | 1” | 9x48 | 1 | 18x36 / 350 | 9–12 | 2.2 |
| M3013-L10SM | 45,000 | 1” | 10x54 | 1.5 | 18x36 / 350 | 12–16 | 2.7 |
| M3015-L10SM | 60,000 | 1” | 12x52 | 2 | 18x36 / 350 | 15–20 | 2.7 |
| M3017-L10SM | 90,000 | 1” | 14x65 | 3 | 18x36 / 350 | 18–23 | 4.2 |
| M4032B-L125 | 30,000 | 1.25/1.5” | 9x48 | 1 | 18x40 / 400 | 9–15 | 2.2 |
| M4036B-L125 | 45,000 | 1.25/1.5” | 10x54 | 1.5 | 18x40 / 400 | 10–15 | 2.7 |
| M4040B-L125 | 60,000 | 1.25/1.5” | 12x52 | 2 | 18x40 / 400 | 15–20 | 4.2 |
| M4042B-L125 | 90,000 | 1.25/1.5” | 14x65 | 3 | 18x40 / 400 | 18–23 | 5.3 |
| M4046B-L125 | 120,000 | 1.25/1.5” | 16x65 | 4 | 18x40 / 400 | 19–25 | 7.5 |
The CLS-100 sizes match the CK10SM sizes up to 60,000 grains and add a 90,000-grain model. The CLS-125 versions use a larger valve and brine tank.
Twin-alternating softeners
Watts sells two twin lines. The W100T series is described as “ideal softeners when soft water is required 24/7, without interruption,” for “residential and light commercial applications ranging from 20,000 to 210,000 grains of hardness removal capacity, at flow rates to 24 GPM” (dealer catalog, PDF page 22). The Locksmith CLSTA-100 series covers the same capacities with the Locksmith controller (dealer catalog, PDF page 21).
| Capacity | Locksmith twin | W100T twin | Tank | Resin | Brine / salt |
|---|---|---|---|---|---|
| 30,000 | M2058-L10T | M2058-W100T | 9x48 | 1 | 18x40 / 400 |
| 45,000 | M2059-L10T | M2059-W100T | 10x54 | 1.5 | 18x40 / 400 |
| 60,000 | M2060-L10T | M2060-W100T | 12x52 | 2 | 18x40 / 400 |
| 75,000 | M2063-L10T | M2063-W100T | 13x54 | 2.5 | 18x40 / 400 |
| 90,000 | M2066-L10T | M2066-W100T | 14x65 | 3 | 18x40 / 400 |
| 120,000 | M2069-L10T | M2069-W100T | 16x65 | 4 | 18x40 / 400 |
| 150,000 | M2070-L10T | M2070-W100T | 18x65 | 5 | 24x41 / 600 |
| 210,000 | M2072-L10T | M2072-W100T | 21x62 | 7 | 24x50 / 800 |
The catalog says capacities and flow rates “are per tank.”
A sizing example
Our arithmetic: a home using 300 gallons a day of 20 gpg water removes about 6,000 grains a day. An M3011-CK10SM at its 30,000-grain maximum would regenerate about every 5 days, using its maximum 15 lb of salt each time. An M3013-CK10SM programmed at 30,000 grains (its minimum) would regenerate on the same schedule but use 9 lb, because the manual lists 9 lb for 30,000 grains from 1.5 cubic feet against 15 lb from 1 cubic foot (WM100SM manual, PDF page 4). The larger resin bed makes the same capacity with less salt. An M3015 would stretch the interval further. Your dealer should run this calculation with your measured hardness, iron and water use, and with the reserve the valve keeps.
What the W100-valve models share
The WM100SM operating manual applies to every W100 softener and sets common site requirements (WM100SM manual, PDF page 6):
- Working pressure from 20 to 125 psi, with a pressure-reducing valve above that.
- Water temperature from 40°F to 110°F.
- At least 10 feet from the water heater “so that hot water does not backup and damage the softener.”
- A 120-volt uninterrupted outlet and an open drain, plus a brine overflow line to drain.
They also share the manual’s warranty terms: 5 years on fiberglass tanks, 5 years on the salt tank and control valve, and 1 year on components, with labor and freight excluded (WM100SM manual, PDF page 2). We did not find a published manual for the Locksmith controller, so ask the dealer for its warranty and settings guide.
Questions to ask before choosing a model
- What hardness, iron and daily water use did you size this for, and how many days between regenerations will that give?
- Why this family? A twin costs more but avoids untreated water during regeneration; a dual-media unit adds carbon for chlorine.
- Is the house plumbed in 1” or larger? The CLS-125 and the largest twins use 1.25” or 1.5” connections.
- Which capacity and salt setting will you program?
OneFlow is not on this list
OneFlow OFRES-K systems are Watts’ salt-free scale-prevention products. They do not remove hardness. If you are comparing a OneFlow with a softener, see Watts OneFlow OFRES-0835 vs 1035 and the Watts brand research page.
How Watts says to choose
The catalog’s notice under the Locksmith tables says: “Selecting a system based on pressure drop alone does not guarantee that the system will provide adequately softened water. System selection should be based on resin quantity, capacity required, feed water analysis, and application requirements.” It adds that “flow rates listed at 25 psi drops are for intermittent peak flow rates and are not to be used as continuous flows.” The W100 page says “model selection is typically based on water hardness, water usage, water source and other factors.”
For pricing and the quote checklist, see our Watts water softener cost guide; for the company and channel, see who makes Watts water softeners.
Frequently asked questions
What is the difference between the M3011, M3013 and M3015-CK10SM?
Size. The catalog lists 30,000, 45,000 and 60,000 grains maximum, with 1, 1.5 and 2 cubic feet of resin in 9x48, 10x54 and 12x52 tanks. All three use the W100 metered valve and an 18x36 brine tank.
What is a Watts Locksmith softener?
A Watts softener line with Watts’ own Locksmith controller and glass-fiber composite valve. The catalog lists CLS-100 models from 30,000 to 90,000 grains, CLS-125 models to 120,000, and CLSTA-100 twins to 210,000.
What does CR-CMP mean on a Watts softener?
The M3011-W100SM-CR-CMP is Watts’ dual-media softener: 1 cubic foot of resin and 0.5 cubic feet of coconut-shell carbon in separate chambers of one 10x54 tank, for hardness plus chlorine, taste and odor.
Which Watts softener gives soft water during regeneration?
The twin-alternating models. Watts describes the W100T series as for soft water “24/7, without interruption,” and the Locksmith CLSTA-100 is its Locksmith-controller twin. Single-tank models deliver untreated water if water is used during regeneration.