How to Change Your Big Blue Filter Cartridge (Video)

Water pressure dropping, or is the cartridge simply due? Steve Parker of Clear Water Filtration walks through a Big Blue cartridge change in about two and a half minutes. The written steps below follow the video in the same order, so you can work at the housing with the page open.

A Big Blue housing is the large blue filter canister on your main water line. Changing the Big Blue filter cartridge on schedule keeps water pressure up and protects the equipment after it. Here is when to change it, what to have ready, each step from the video, and when a filter problem needs a service call instead.

When to Change Your Big Blue Filter Cartridge

There are two usual reasons to change it. Either the water pressure in the house has dropped, or enough time has passed that the cartridge is due. Sediment and carbon filters should be replaced every 6-12 months. If the old cartridges come out dark or orange from sediment or iron well before that, change them sooner.

A fall change sends the system into winter with a clean cartridge. If you are getting ready for the cold, see our guide to winterizing your water filtration system.

What to Have Ready

• A replacement cartridge of the same size and type as the one in the housing (read the label on the old cartridge).
• The black filter wrench, which is usually kept somewhere near your equipment. If you cannot find it, give us a call and we can mail you one.
• A bucket for the water in the housing.
• A clean cloth for wiping the O-ring.

Step by Step: Changing a Big Blue Filter Cartridge

1. Find the ball valve, or isolation valve, upstream of the filter and close it.
2. Find the valve downstream of the filter and close that as well. Water is now off to the filter.
3. Press the red button on top of the filter housing. Air and water escape, relieving the pressure inside the housing.
4. Fit the filter wrench underneath the housing and turn it to unscrew the housing.
5. Once the housing is loose, remove the wrench and keep unscrewing by hand. The housing is full of water and fairly heavy, so support the bottom with one hand and unscrew with the other.
6. The housing, or sump, drops away along with the O-ring. Take out the O-ring, pull out the old Big Blue filter cartridge and dump the water into the bucket.
7. Wipe the O-ring clean and inspect it for wear or debris. Once it looks okay, reinstall it.
8. Insert the new cartridge and screw the housing back on hand-tight.
9. Snug it with the wrench, not too much: about an eighth of a turn.
10. Turn the valve feeding the unit back on first, then the valve after the unit.

That is the whole change: two valves, one button, one wrench and a fresh cartridge.

When to Call Instead

A cartridge change is routine, but some filter problems are not. Call for filter system service and repair in Vermont when the housing is cracked or still drips at the cap after a careful change, or when water pressure does not come back with a fresh cartridge. Cartridges that plug up or turn orange within weeks point to iron or sediment that a cartridge cannot keep up with, and the lasting fix is usually iron removal for Vermont well water rather than more cartridges. A free in-home water test shows what is in your water first. Our technicians work on all makes and models and can usually schedule same-day. You can request service online or call 802-496-5544.

More How-To Videos

Our how-to videos page also covers the K5 filter change, the Kinetico backwash and a standard cartridge change, and the written guide on how to bypass your Clack water softener follows the same format as this one. If the housing itself needs replacing, see our whole house water filtration systems.

Service Locations:
Vermont: Washington, Lamoille, Addison, Orleans County, Caledonia, Chittenden, Essex, Franklin, Grand Isle, Orange, Rutland, Windham, Windsor