028105 SITA UV 412, 440, 450, 480, 550, and 40/80 40w and 80w Systems - Replacement Quartz Sleeve

This is the direct replacement quartz sleeve for SITA UV 412, 440, 450, 480 and 550 systems, as well as the 40/80 range in both 40W and 80W versions, matching SITA's own part number 028105. WrekinWater lists it against the QJ23900DE-028105 reference so it's easy to order the right sleeve for your specific SITA unit. It has a domed end, the same style used across this SITA family.

Signs your quartz sleeve needs replacing

• The sleeve has turned cloudy, hazy, or visibly scratched.
• Brown or yellow discolouration is building up on the outside of the glass.
• The UV monitor or alarm on your SITA unit is triggering with the lamp still lit.
• It's roughly 12 months since the sleeve was last replaced, the standard interval for UV maintenance.

Across the SITA 412 to 550 and 40/80 ranges, this sleeve is what keeps the UV lamp dry while allowing UV light through to treat the water flowing over it. Limescale, iron, and general fouling gradually reduce how much UV light gets through, so disinfection performance can drop well before the lamp itself shows any obvious sign of failing. Because SITA's 40/80 systems run at both 40W and 80W, a fouled sleeve on the higher-output version can still leave water under-treated even with a fully working lamp.

WrekinWater has stocked parts for established water treatment brands including this SITA range for over 15 years, and matching the correct 028105 / QJ23900DE-028105 reference avoids the guesswork of ordering by system name alone. As a Trustpilot-rated family business, we're happy to confirm which SITA model you have if the part number on your unit isn't clear.

How to replace it

1. Isolate the water supply to the SITA unit and drain the housing.
2. Undo the retaining nut or union and withdraw the lamp, then the old sleeve.
3. Wipe out any scale or residue from inside the housing before fitting the replacement.
4. Fit new O-rings and insert the new sleeve, domed end first.
5. Refit the lamp, restore water and power, then run the system to drain briefly before normal use.