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Instructions for Replacing Your Undersink Water Filter Cartridge

Product Codes: USC2000 I ASC1000 I ASC2000 I ASC3000 I ASC4000 I ASC7000 I ASC-CER | GAC-USC

Please note: VIDEO Instructions are also available

To Change Your Under Sink Cartridge

A)   Turn off the water supply to the filter.

B)   Open the counter top filter tap – to relieve the water pressure

C)   Positioning a bucket or bowl underneath - to catch any water spillage - unscrew the bottom of the filter housing from the cap and remove the old cartridge. (Turn clockwise to loosen ie turn housing to the left)

Note If the housing seems stuck bear in mind it is like a stuck water tap – ie after one hard push it will be back to normal. Be careful not to damage the unit eg don’t use any sticking out ports / pipe holes for leverage. If necessary you could heat up the bottom of the filter housing in hot water to expand it. Or use a car oil changing type spanner… or even contact us to borrow a special spanner.

D)   Wash the housing and top thoroughly. (You could use Milton or diluted bleach). Rinse well.

E)   Place your new cartridge into the lower housing. Simply make sure that the hole in the middle of the cartridge fits over the slot / standpipe at the bottom.

(TIP: Make sure that any rubber washer that is on some cartridge types - at the top and/or bottom - is in place).

F)    Place the cap back onto the housing. Again, simply make sure that the cartridge is in place – ie so that the hole at the top of the cartridge fits into the slot / standpipe under the cap. 

Screw top and housing together. Screw hand tight. Do not overtighten

TIP: add a dab of Vaseline to the screw thread to make it easier to undo next time.

G)   Once this is done turn on the water supply to the filter. Look for leaks. If there is a leak the housing should be tightened further.

H)   Run about 2 gallons of water (approximately a sink full) to flush the cartridge of any “carbon fines” - these are tiny black particles, quite normal and safe. If they show at all they will soon be flushed away.

Your filter is now safe to use. Note when it’s time to change again.

NOTE: If you are away for anything longer than a weekend always flush the cartridge through on your return - as per (H) above.

Any Problems? Please Telephone 020 8761 6611

Important Note re Reminders

To avoid long term bacteria build-up it is important to change or disconnect your water filter on time.

We will email you reminders when it's to change, but please make sure you whitelist our email address so these reminders aren't sent to spam.

And/ or set an alarm now on your mobile or use Siri etc

Please note your feedback and any suggestions as to how we can improve our service are always appreciated.


Thank you

Sales Admin Team
Telephone 020 8761 6611

Water Filter instructions / Guides for fitting and installing


Need advice?
Please call us on
020 8761 6611


UK Water Filters Ltd
Unit D120
Parkhall Industrial Centre
SE21 8DE

UK Water Filters Ltd a Company Limited by Guarantee,
Registered in England,
Company Number: 05249436,
VAT Reg. No. 863 7634 91


Questions? Call us for friendly advice
+44 (0) 20 8761 6611




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