QJ23800 - Replacement Quartz Sleeve for UV Systems Ltd model 336/4S

The QJ23800 is a direct replacement quartz sleeve for the UV Systems Ltd model 336/4S disinfection unit, supplied by WrekinWater. It fits over the UV lamp to keep it dry and isolated from the water stream while still allowing UV light to pass through and treat the water. If your 336/4S sleeve has clouded, scratched, or scaled up, this is the correct part to restore proper UV output.

Signs your quartz sleeve needs replacing

• The sleeve looks cloudy, hazy, or milky rather than clear glass.
• You can see scale, scratching, or a brownish film building up on the outside.
• The UV monitor or alarm on the 336/4S unit is triggering even though the lamp lights up.
• It has been in place for around 12 months or longer, the usual replacement interval.

The quartz sleeve's job is to keep the UV lamp completely dry while letting UV-C light pass straight through into the water. Hard water scale, iron, and general fouling build up on the outside of the sleeve over time, and the quartz itself can dull or micro-scratch with age and cleaning. As transmittance drops, less UV energy actually reaches the water, so the lamp can be lit and appear to be working normally while disinfection quietly becomes unreliable.

WrekinWater is a family-run water treatment specialist based in Bettisfield, Shropshire, that has supplied parts and support to more than 50,000 customers over 15 years. Ordering the QJ23800 from WrekinWater means you get the correct sleeve matched to the UV Systems Ltd 336/4S rather than a guessed generic fit, backed by a company rated Excellent on Trustpilot.

How to replace it

1. Isolate the water supply to the UV unit and switch off and unplug the power to the system.
2. Undo the retaining nut or union at the end of the housing and carefully withdraw the UV lamp first.
3. Slide out the old quartz sleeve and set it aside for disposal.
4. Wipe out the inside of the housing and fit new O-rings to the sleeve or housing as supplied.
5. Insert the new QJ23800 sleeve, then carefully refit the lamp and reassemble the retaining nut.
6. Restore the water supply and power, check for leaks, and run to drain briefly before using the water.