Kinetico Main Base Seal - 2020C, Mini-KB, Aqua-Blu, BSS models + all commercial Part Number 8633

The Kinetico Main Base Seal (Part No. 8633) is an essential replacement O-ring that forms a watertight seal between the control valve head and the resin tank base on Kinetico twin-tank water softeners using the 2020C valve assembly. This genuine-spec seal prevents internal leaks and ensures your Kinetico system continues to deliver perfectly softened water day after day.

Technical specifications

Symptoms that mean you need this part

• Continuous water flow to drain
• Hard water at your taps
• Leaks between the valve head and tank
• Reduced system performance or regeneration failure

Why it fails / why it matters

The main base seal is the primary watertight joint between the control valve and the resin tank. Constant exposure to mains pressure and chlorinated water gradually hardens the elastomer, and once it loses its seal, hard water can bypass into your softened supply or leak out at the tank joint.

Why buy this from WrekinWater

WrekinWater has served more than 50,000 customers over 15 years from its base in Bettisfield, Shropshire, and stocks genuine Kinetico seals and internal valve parts alongside Pentair Fleck, Autotrol and Clack components. As a UK-registered company (Company No. 11000488) rated Excellent on Trustpilot, we help you get the exact seal your valve needs.

How to fit it

1. Isolate the softener at the bypass valve and relieve system pressure
2. Lift the control valve head clear of the resin tank
3. Remove the old seal and clean both sealing surfaces thoroughly
4. Lubricate the new seal with food-grade silicone grease (never petroleum jelly)
5. Seat the O-ring evenly to avoid twisting or pinching
6. Refit the valve head and restore the water supply, checking for leaks