The short answer
A WS1 rebuild replaces the spacer stack and piston (and seals); match the part numbers to your WS1 version before ordering.
Signs
- Leaking to drain.
- Hard water with salt and settings fine.
- Error codes after a stuck cycle.
Parts
Better Home Water Treatment WS1 for Clack WS1 Valve Rebuild Kit, Clack V3005 for Clack WS1 Valve Part, GUO SHUY WS1 for Clack WS1 Valve Rebuild Kit. Clack part numbers start with V; check your valve's manual.
Before ordering
The WS1 and WS1.25 don't share pistons; confirm your size on the valve label.
Products mentioned
Questions readers ask
Is a Clack WS1 easy to rebuild?
Most owners can replace the spacer stack and piston with the manual and the right wrench.
Do all WS1 valves take the same piston?
Pistons differ by function and size; match the part number.