WS1 Drain Line Flow Controller (DLFC) 007 (0.7 gpm) for 3/4

The Clack WS1 DLFC 007 is a low-flow drain line controller rated at 0.7 gpm, sized to fit 3/4in drain fittings on compact Clack WS1 control valves. WrekinWater stocks it as a genuine replacement disc for smaller-capacity WS1 softeners that need a gentler, tightly controlled backwash flow. It's the correct rating for units where the standard higher-flow DLFCs would be far too aggressive.

Signs you need this part

• Backwash flow to drain looks stronger than it should for a small unit.
• Resin is escaping into the drain during regeneration.
• The unit regenerates but softening performance drops off quickly afterwards.
• The fitted DLFC disc is cracked, worn smooth or missing.

On a compact WS1 softener the resin volume is small, so the drain flow during backwash has to be tightly restricted to avoid lifting the bed too far. The 0.7 gpm DLFC is what keeps that flow gentle and controlled; once the disc wears or cracks it stops regulating properly, letting resin wash away and the bed settle unevenly.

WrekinWater has fitted and supplied Clack WS1 parts to households across the UK for more than 15 years from our Bettisfield, Shropshire base, and we're rated Excellent on Trustpilot. Getting the flow rate right matters more on smaller units, so we stock the exact 0.7 gpm rating rather than a generic substitute.

How to fit it

1. Switch the softener to bypass and isolate the incoming water supply.
2. Find the 3/4in drain line elbow fitting on the back of the valve.
3. Release the elbow and pull out the old DLFC 007 disc.
4. Push the new 0.7 gpm disc into the elbow the same way as the original.
5. Refit the elbow securely and turn the water supply back on.
6. Run a manual regeneration cycle and check the joint for leaks.