Kinetico DO Cap Part Number 9044B

The Kinetico DO Cap (Part No. 9044B) is a genuine replacement Discharge Outlet cap designed for Kinetico twin-tank water softeners fitted with the 2020C-series control valve. This precision-moulded cap secures the discharge outlet port and houses the DO Cap Seal (Part No. 8628), creating a reliable watertight closure that prevents leaks and maintains consistent system pressure.

Technical specifications

Symptoms that mean you need this part

• Water leaking from the side of the control head
• Visible cracking or deformation of the existing cap
• Loss of pressure during service or regeneration
• You're replacing the O-ring (8628) — it's good practice to fit a new cap at the same time

Why it fails / why it matters

The DO cap holds the internal seal in place and takes the ongoing pressure of every service and regeneration cycle. Over time the polymer can crack or deform, particularly if it's been over-tightened or the internal seal has already started to fail, letting water escape at the discharge outlet.

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 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 part your valve needs.

How to fit it

1. Isolate the softener at the bypass valve and relieve system pressure
2. Ensure the O-ring (Part No. 8628) is installed and lubricated with food-grade silicone grease
3. Fit the new cap and tighten evenly and securely by hand — do not over-tighten
4. Restore the water supply and check for leaks