Changing a Water Filter and Water Filter Cartridge

How to Change a Water Filter Cartridge Instructions

By Mark J. Donovan

Changing a water filter, such as an Aqua-Pure from Cuno is relatively simple.

First, make sure no one runs any water while you are changing the filter. Once this has been done, place a small bucket under the water filter and turn the valve to the off position. If there is a purge valve on top of the filter, push on this for a second or two. This will relieve pressure in the filter. Make sure you unscrew the base unit counter-clockwise.

It should only be hand tight, though sometimes the water filter manufacture may provide a plastic custom wrench for loosening/tightening it up.

Once the base as been unscrewed, remove the filter cartridge and drain out most of the water. I typically leave a little water in the base so that I can swirl it and remove the majority of the sediment that may be caked in at the bottom. After swirling, drain out the contents into the bucket.

Next carefully remove the O-Ring from the top of the base unit. Clean this off with a rag thoroughly.

Now take a large dry rag or towel and insert it into the base unit. Insert it in a swirling motion so that you can clean the sidewalls of the base unit.

Next smear a little Vaseline all around the O-Ring. This will ensure that the O-Ring moves freely when the base is reattached to the top of the filter unit.

Place the O-Ring back onto the base filter unit. Then insert the new filter cartridge.

Next, screw on the base filter unit to the top unit. Hand tighten only. Do not over tighten as this could damage the unit or crimp the O-Ring causing a small leak.

Finally, slowly turn the water filter to the on position. If there is a purge valve, pushing on this while turning on the filter may enable the air to escape through the valve. Doing this will eliminate the knocking sound otherwise heard in the pipes until the air is flushed out of them. This will happen with normal use of the water and is of no concern.

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