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Instructions for Replacing INST-WH-CART whole house cartridges

Product Codes: FIL16/SC16 and FIL32/SC32

Thank you for your purchase.

How to Replace Your Whole House Cartridges

In addition to the step by step below, Video Instructions are also available here


Cartridge ONE (Code FIL16 or FIL32) 

This is the special mix of carbon and ceramic that filters the water.

Change Cartridge One every 12 months or if you notice any deterioration in the water.

This cartridge is in the housing unit on the LEFT as you look at the unit. This is where the water enters the system. 


Cartridge TWO (Code SC16 or SC32) 

This holds the special anti-scale media.

Note the cartridge is only one third or so full.

This is correct. (The media needs to move freely with the water in order to work properly. 



Turn off the water supply and place a bucket under the filter housing to catch any water spillage. 

Then press any buttons on top of the housing - for a few seconds - to release pressure. (If there are any buttons - it depends on your housing type - they might be red or black). 

Use the spanner/wrench to unscrew the lower housing.

NOTE You will be turning it anti-clockwise ie to the left (as per “Lefty loosey / righty tighty” . 

Discard the used cartridge (you can return it to us for recycling, later when it’s dried out). 

Place the new cartridge in the housing - noting the top and bottom correctly.

Make sure it is seated correctly in the bottom slot

Carefully guide the top of the cartridge up into the centering slot making sure you guide it carefully past any centralising prongs. 



Optionally, before closing smear some Vaseline around the large black rubber o-rings to lubricate them.

You can also dab some on the screw threads to make it easier to open next time (but do not put Vaseline on the cartridges themselves). 

Once you are sure the cartridge is seated correctly inside the housing, tighten it by hand, then use the wrench to tighten it reasonably - don’t overtighten. 

Note re Blue Head / White Bottom style Housings: A fully closed housing has a gap of 2mm to 3mm max between the lower blue nut and the blue top.

You can get fairly close to this gap screwing it by hand. Then use the wrench to give it a final tightening.

BUT if you need to use a lot of force with the wrench to achieve that 2mm / 3mm then there is a problem. If so check the internal cartridge is inserted correctly. 

Note re Black Head / Blue bottom style Housings: When closing the housing up, watch out for the prongs / guides under the black header unit. A loose cartridge might mis-align and be damaged / pierced by them. 

When closed turn the water supply back on. (If you have a bypass valve make sure it is turned back on). 

Open up your cold water taps for 5 minutes and flush toilets to let any trapped air escape. The water may look cloudy for a while but will settle down.


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 cartridges on time.

We will email you reminders when it's time 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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