The Fleck 9100 SXT is a twin-tank water softener control valve built to deliver truly continuous, 24/7 soft water. Two resin tanks alternate so one is always in service while the other regenerates, meaning there is never a hard-water bypass or a "reserve" to calculate — the moment the online tank nears exhaustion, the valve instantly switches to the freshly regenerated tank. Its electronic SXT digital controller meters your actual water use and regenerates strictly on demand, using soft water from the in-service tank for a cleaner, more efficient recharge. Built on a corrosion-free, glass-reinforced polymer body, this configuration includes the valve cover and ships Less Drain Line Flow Control (DLFC) so you can match the drain button precisely to your tank size.
Key Performance Metrics
Valve Construction & Configuration
| Control Type | SXT electronic digital metered controller — on-demand (immediate) regeneration, as often as every 90 minutes if required |
| System Configuration | Twin (dual) alternating tank, six-cycle |
| Valve Body Material | Corrosion-free, UV-resistant glass-reinforced polymer (Noryl) |
| Regeneration Water | Regenerates each tank with soft water from the in-service tank |
| Brine / Injector System | 1600 brine system, 3/8" brine line |
| Distributor / Riser Tube | 1.05" O.D. pilot (32 mm), 3/4" riser tube |
| Mounting Base | 2-1/2" – 8 NPSM; sits approx. 7.3" above tank top |
| Drain Line Connection | 1/2" NPTF (Drain Line Flow Control not included — order to match tank size) |
| Meter Range | 0.25 – 15 GPM (3/4" paddle) or 0.7 – 40 GPM (1" paddle), ±5% |
| Maximum Tank Diameter | 6" – 16" |
| Operating Pressure | 20 – 125 psi (1.4 – 8.5 bar) |
| Water Temperature | 34 – 110°F (1 – 43°C) |
| Cover | Included |
| Part Number | 910006-003 |
Why Choose a Twin-Tank 9100
Continuous Soft Water
With two tanks alternating, soft water is available around the clock — even during regeneration. There's no hard-water bleed-through and no downtime, which single-tank softeners can't match.
Metered On-Demand SXT
The SXT digital controller tracks gallons used and regenerates only when the resin is actually depleted, so you use the least possible salt and water for your real demand.
Regenerates with Soft Water
Each tank is recharged using softened water drawn from the tank still in service — keeping the resin bed and injector cleaner and extending the life of the system.
No Reserve to Size
Because a fully regenerated tank is always waiting in the wings, there's no reserve capacity to calculate — you get the full rated capacity of each tank between regenerations.
Corrosion-Free Body
The glass-reinforced polymer (Noryl) valve body resists corrosion and UV, standing up to years of continuous cycling in demanding residential and light-commercial duty.
Cover Included, Less DLFC
Ships with the valve cover for a finished look and protected internals, and without a drain line flow control so you can dial in the exact backwash rate for your tank size.
Getting Set Up
- Mount the 9100 control onto both mineral tanks using the tank adapters, seating each 3/4" distributor/riser tube so it's cut flush, chamfered, and centered in the valve.
- Select and install the correct Drain Line Flow Control button for your tank diameter (sold separately) — this sets the backwash rate that lifts and cleans the resin bed.
- Connect the inlet and outlet plumbing to the 3/4"–1-1/4" ports, run the 1/2" drain line, and connect the 3/8" brine line to the brine tank.
- Power up and program the SXT controller: set the time, your water hardness, and system capacity — the meter then calculates on-demand regeneration automatically from actual usage.
Where the 9100 SXT Fits
The 9100 SXT pairs with mineral tanks from 6" to 16" in diameter and is the right choice anywhere soft water simply can't be interrupted — busy households with high or round-the-clock demand, small commercial sites, salons, cafés, laundries, and light-industrial process water. Because it's a twin-tank demand system, there's no reserve capacity to estimate and no hardness break-through during regeneration: when the online tank nears exhaustion, the valve immediately brings the second, fully regenerated tank into service. This unit ships Less Drain Line Flow Control, so add the DLFC button matched to your tank, and confirm your incoming supply falls within the valve's 20–125 psi and 34–110°F ranges before installation.
Pro Tip: Because the 9100 regenerates one tank using soft water from the other, the resin and injector stay cleaner than on single-tank systems — just keep the brine tank topped up so back-to-back regenerations always have salt available during your heaviest-demand days.
