QS-330D Domed En compatible Viqua Sterilight Quartz Sleeve, for Model SC4 & SC4/2, S2Q, SSM-17, and VT4 using S330RL (QJ23362DE)

This is the QS-330D domed-end quartz sleeve for Viqua Sterilight UV systems, sold by WrekinWater under part code QJ23362DE. It is the correct sleeve for units running the S330RL lamp, including the SC4, SC4/2, S2Q, SSM-17 and VT4 models. Fitting a fresh sleeve keeps the S330RL lamp's UV output reaching the water instead of being blocked by a fouled or aged sleeve.

Signs your quartz sleeve needs replacing

• The domed sleeve has turned cloudy or yellow-brown instead of staying clear.
• There is a visible ring of limescale or iron staining around the sleeve.
• Your SC4, S2Q or VT4 controller is showing a low UV intensity warning despite a working S330RL lamp.
• Water starts to taste, smell, or look slightly off even though the lamp is lit and the system seems fine.

On Viqua Sterilight units, the quartz sleeve sits between the S330RL lamp and the water, keeping the lamp dry and electrically safe while letting UV-C light through to disinfect. Minerals in the water gradually scale the outside of the sleeve, and the quartz itself can fog or scratch with age, both of which cut down how much UV light actually reaches the water. The lamp can be glowing perfectly well while the sleeve quietly starves the water of effective UV dose.

WrekinWater stocks genuine-fit sleeves for Viqua Sterilight and other major UV brands, drawing on 15 years of experience serving over 50,000 customers from its base in Bettisfield, Shropshire. Buying the correct QS-330D for your SC4/2 or VT4 unit avoids the guesswork of an ill-fitting generic sleeve, from a supplier rated Excellent on Trustpilot.

How to replace it

1. Turn off the water supply to the UV chamber and disconnect power to the unit.
2. Loosen the retaining nut or union at the base of the housing and slide out the S330RL lamp first.
3. Withdraw the old QS-330D sleeve from the housing and clean out any scale or debris inside.
4. Fit new O-rings to the sleeve ends before inserting the replacement domed sleeve.
5. Carefully reinsert the S330RL lamp and refit the retaining nut or union securely.
6. Restore the water supply and power, check the joint for leaks, and run water to drain briefly before use.