The Fleck 2510 is a proven, mid-size downflow softener control valve that has been a workhorse in residential and light-commercial systems for decades. This configuration runs a rugged 12-day mechanical time clock — an electromechanical drive with heavy-duty plastic gears and a single hydraulically-balanced piston — for dependable, schedule-based regeneration with no circuit boards to fail. Built on a non-corrosive, UV-resistant fiber-reinforced polymer body, it flows up to 19 GPM and fits softener tanks up to 16" in diameter. It ships with a 120V U.S. power cord, hardwater bypass, 1650 brine valve, #1 injector, 0.50 GPM brine flow control, and an environmental backplate — Less Cover and Less Drain Line Flow Control (DLFC), so you can add the exact drain button and cover your build needs.
Key Performance Metrics
Valve Construction & Configuration
| Control Type | 12-day electromechanical time clock — rugged design with heavy-duty 3/8" wide plastic gears; regenerates on a fixed calendar schedule |
| Regeneration | Downflow / co-current, fully adjustable 3- or 5-cycle |
| Valve Body Material | Non-corrosive, UV-resistant fiber-reinforced polymer |
| Piston | Single, time-tested hydraulically-balanced piston |
| Injector | #1 injector |
| Brine System | 1650 brine valve, 3/8" brine line, 0.50 GPM brine flow control (BLFC) |
| Bypass | Integral hardwater bypass (raw water available during regeneration) |
| Distributor / Riser Tube | 1.05" O.D. pilot, 3/4" riser tube |
| Mounting Base | 2-1/2" – 8 NPSM |
| Drain Line Connection | 1/2" NPTF (Drain Line Flow Control not included — order to match tank size) |
| Power | 120V / 60 Hz, U.S. power cord |
| Operating Pressure | 20 – 125 psi (300 psi hydrostatic rated) |
| Water Temperature | 34 – 110°F (1 – 43°C) |
| Maximum Tank Diameter | Up to 16" (softener and filter) |
| Cover | Not included — ships with environmental backplate only (Less Cover) |
| Part Number | 251001-002 |
Why the 2510 Endures
Proven Mechanical Reliability
A simple electromechanical timer with heavy-duty plastic gears and one hydraulically-balanced piston means fewer things to fail and a valve that keeps running for years.
Corrosion-Free Body
The fiber-reinforced polymer body resists corrosion and UV, holding up to continuous service in residential and light-commercial installs.
12-Day Time Clock
Regenerates on a set calendar schedule with no electronics — ideal where water use is steady and predictable and low-maintenance operation matters.
Adjustable 3- or 5-Cycle
Fully adjustable cycle programming lets you tune backwash, brine draw, and rinse to your resin and water conditions for efficient regeneration.
Hardwater Bypass
An integral bypass keeps water flowing to the building during regeneration, so supply is never interrupted on a single-tank system.
Build-It-Your-Way
Ships Less DLFC and Less Cover so you can match the drain flow control to your exact tank size and add the cover that suits your installation.
Getting Set Up
- Mount the 2510 onto your mineral tank over the 3/4" distributor/riser tube, making sure the riser is cut flush, chamfered, and centered so it seats cleanly 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 1650 brine system.
- Plug into 120V power and program the 12-day time clock: set the current time, the regeneration time, and the days between regenerations based on your hardness and water usage. Add an environmental cover if the valve will be exposed (Less Cover).
Where the 2510 Fits
The 2510 suits softener (and filter) tanks up to 16" in diameter, making it a versatile mid-size valve for larger homes and light-commercial softeners. As a time-clock control it regenerates on elapsed days rather than metered gallons, so it's best where demand is steady and predictable — size the day interval to your water hardness and usage so you regenerate before the resin bed is exhausted without wasting salt and water. This unit ships Less DLFC and Less Cover, so add the drain button matched to your tank and the cover of your choice, and confirm your incoming supply falls within the valve's 20–125 psi and 34–110°F ranges before installation.
Pro Tip: The 2510's electromechanical timer and single hydraulically-balanced piston are famously serviceable — seal kits and parts are widely available, so this valve can be rebuilt rather than replaced and run for many years. Since it ships Less Cover, remember to add an environmental cover if the valve will sit anywhere exposed to dust or moisture.
