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Replacement UV Lamp for Watts WUV12-230

Replacement UV Lamp for WUV12-230 12 gpm UV system.



Product SKU: GPH843T5L-4



This is the replacement lamp (Philips GPH843T5L/4 for Watts PWUVBULB12) for the Watts UV disinfection system WUV12-230.

Lamps are easy to replace and are rated for a 12 month (9,000 hours) continuous service life. You must change your lamp every 12 months as risk of the lamp not working effectively after this time is HIGH and your water may not be safe. You must also have a pre-filter installed with a minimum of 5 micron filtration and the reason for this is that any sediment in your water will coat the inside of the UV systems quartz sleeve making the UV ineffective and your water unsafe.

You can purchase this with a quartz sleeve. Please see product options. Alternatively, if it's just a sleeve that you're after you can purchase these separately.

45 Litres per minute UV system.

Power output - 40 watts

Length - 843mm

Base - 4 pins single ended

Also known as GPH843T5L/4 HA, GPH843T5L/4 LT or GPH843T5L/LS/40W


  • Well water
  • Homes
  • Water Systems
  • Aquaculture
  • Food Service
  • Water coolers
  • Reverse Osmosis (RO) systems

Replacing your UV lamp and servicing your UV system

Handle the quartz sleeve and lamp by the ends only. Avoid touching the sides.

  1. Disconnect power.
  2. Turn your water off and open valve downstream of system to relieve pressure.
  3. Remove the vinyl cap and unscrew the nut.
  4. Pull out lamp about 2" from the chamber.
  5. While holding lamp carefully remove lamp socket on exposed end.
  6. Pull lamp from chamber.
  7. Remove O ring from the end of the quartz sleeve.
  8. Remove quartz sleeve.
  9. To fit a new quartz sleeve/lamp follow steps 8 to 1 in reverse.


To get the best out of your UV system we recommend the following:

  • The quartz sleeve should be cleaned with glass cleaner every 6-12 months. Replace after 24 months.
  • Replace your lamp every 8,000-9,000 hours of operation (approximately 12 months of continuous service).

UV lamps and quartz sleeves are delicate and therefore easily damaged. So, be really careful when you're removing and replacing them.

This lamp is shipped directly to you via our suppliers to reduce handling time. 


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