How To Change a Water Softener Filter

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Most water softeners come with a built-in sediment pre-filter that removes sediment from water before it enters the softening system.

Changing a water softener filter is essential to protect the softening resin from sediment damage, which could damage the resin’s lifespan.

📌 Key Takeaways:

  • To change a water softener filter, switch off your whole home water supply and depressurize the filter, then remove the old filter and slot the new filter in its place. Turn the water supply back on.
  • Regularly changing the filter cartridge in a water softening system will prevent sediment from damaging the resin.

📋 What You Need to Change a Water Softener Filter

There are a few parts and accessories you’ll need to change the water filters in your water softener system.

We’ve explained what you’ll need, and why, below.

  • Filter wrench – Most water softeners come with a wrench for the pre-filter housing. The wrench is plastic, so it won’t damage the housing when you use it to unscrew it from the unit. If your softener doesn’t come with a filter wrench, try unscrewing the filter by hand or (very carefully) using a metal wrench.
  • Bucket – Expect a bit of water spillage when you disconnect a water softener filter. You can catch excess water with a bucket or tub.
  • Lubricant – Over time, the o-rings securing the filter inside the housing will become dry and won’t form a proper seal due to increased surface friction. You can use a lubricant to prevent abrasion and decrease the surface friction, helping the o-ring to stay gripped in place.
  • New o-ring – The time will come when you eventually need an extra o-ring to swap out the old one. You can buy a pack of o-rings for water filters in hardware stores for less than $10.
  • New filter – Finally, you’ll need to replace an old or faulty filter with a new water filter cartridge. Make sure the new filter is correctly sized to fit inside the existing filter housing.
Parts and tools used to changing a water softener filter

📖 How To Change Water Softener Filter: Step By Step

To change the filter in a water softener, follow these steps:

Step 1: Shut Off Your Water

First, shut off your main water supply to prevent leaks during the filter change.

You should find your water supply valve near your water meter inside your home, at the main water pipe’s entry point.

How To Change Water Softener Filter Step 1_ Shut Off Your Water

Step 2: Depressurize The Water System

Relieve pressure from the water supply line by opening your nearest faucet.

Wait a couple of minutes for water and air to escape from the pipes. This will prevent a lot of water from leaking out of the pipe when you replace the filter.

The filter housing’s inlet cap might also have a pressure release button (which is usually red or black). Press this button to relieve pressure inside the filter system.

How To Change Water Softener Filter Step 2_ Depressurize The Water System

Step 3: Detach The Water Filter Housing

Next, detach the filter housing from the softening system. Make sure to place a bucket or a large towel underneath the housing to catch water leaking from the unit.

Using the included filter wrench, unscrew the filter housing sump from the cap. You should be able to loosen the filter by turning the filter wrench clockwise.

Once the filter housing is loosened, hand-turn the housing until it comes completely away from the cap. Be careful – it’ll be full of water.

How To Change Water Softener Filter Step 3_ Detach The Water Filter Housing

Step 4: Remove The Old Filter

You should find the old filter cartridge inside the housing. Tip the housing upside down to remove the old cartridge and o-ring. Hold it over the bucket to catch any leaking water.

How To Change Water Softener Filter Step 4_ Remove The Old Filter

Step 5 (Optional): Wash The Housing

If the filter housing is dirty or the threads are obstructed with sediment, soak the housing in hot, soapy water, then sponge off the debris and rinse the housing with clean running water.

Thoroughly dry the housing before moving on to the next step.

How To Change Water Softener Filter Step 5 (Optional)_ Wash The Housing

Step 6: Grease Or Replace The O-Ring

Assess the quality of the removed o-ring. If it’s still in good condition, grease the o-ring with lubricant and put it back in the housing, making sure it’s seated properly.

Or, if you notice cracks or damage, replace the o-ring with a new one.

How To Change Water Softener Filter Step 6_ Grease Or Replace The O-Ring

Step 7: Insert The New Filter Cartridge

Slot the new filter cartridge into the filter housing until you hear it click in place.

How To Change Water Softener Filter Step 7_ Insert The New Filter Cartridge

Step 8: Re-Attach The Housing

Twist the filter housing back onto the softening system, hand-tightening it in place. You shouldn’t need to use the filter wrench for this – it could damage the housing and make it difficult to remove next time.

How To Change Water Softener Filter Step 8_ Re-Attach The Housing

Step 9: Turn On Your Water

You should now be ready to turn on your water supply.

Open the water supply valve slowly, then open a nearby faucet until water flows out.

Check for leaks around the sediment filter. If you notice any, shut off your water and hand-tighten the housing again.

And that’s it! You’ve successfully replaced the water filter in your softener system, and your water quality should now be restored.

How To Change Water Softener Filter Step 9_ Turn On Your Water

❔ How To Change Water Softener Filter: FAQ

How often should you change a water softener filter?

You should change the sediment water filter cartridge on your water softener every three to six months, or according to the manufacturer’s advice. The size and surface area of the sediment filter, your water usage, and your water’s sediment content will all affect how quickly the media becomes clogged and how often you have to change your water filter.

How do you know when you need to change a water softener filter?

Signs you need a new water softener filter are reduced water pressure, unpleasant taste or odor of your water, and a dirty-looking filter cartridge. Always replace your filter when advised by the manufacturer, even if you don’t notice any change to your water quality.

What happens if I don’t change my water softener filter cartridge?

If you don’t change the water filter cartridge in your water softener, it’ll eventually become useless at trapping sediment. As a result, water containing sediment will flow into the water softening system and potentially damage the resin beads.

Do you need a water softener filter if you have a whole house water filter?

It depends. If your whole house water filtration system is installed downstream of the water softener, then it won’t protect the softener from contaminants that could damage the resin. Plus, the whole house water filter might not remove sediment. However, if you have high sediment and iron, and you install a separate whole house filtration system (including a sediment filter) upstream of a water softener, the sediment filter may not be necessary.

  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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