How Often to Change Whole Home Water Filters

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Whole home water filtration systems boost the safety of treated water, filtering out heavy metals and germs. An important component of owning a filtration system is to change out its filters on a regular basis.

Filtration systems can be composed of many different individual filters. The most common filter—plus, the one that needs to be replaced most frequently—is the sediment pre-filter.

What a Whole Home Water Filtration System Is

A whole home water filtration system is a water treatment system that is installed where the main water line enters the house. It treats all water within the house, filtering out chlorine taste, odors, zinc, copper, cadmium, and mercury, plus other impurities. 

Residential whole home systems treat municipal water that has been previously treated, not well water. But they can be adapted to treat well water.

How Often to Change Whole Home Water Filters

Whole home water filters and related parts must be replaced on a schedule unless other factors require more or less frequent replacement.

  • Pre-filter: Every 3 to 9 months
  • Post-filter: Every 6 to 12 months
  • Filtration tanks: Every 5 to 10 years
  • UV filter (lamp): As needed (about once a year)
  • Salt-free water softener filtration tank: Every 6 years

Sediment Pre-Filter

Replace the pre-filter (or sediment pre-filter) every three to six months. Depending on use, the pre-filter may last up to nine months before needing to be replaced.

The first line of defense as water enters the home, the pre-filter is located between the water shut-off valve and the water filtration system. The pre-filter is a cartridge-style filter that traps dirt and debris as small as five microns. All systems have a sediment pre-filter.


Replace the sub-micro post filter every six to 12 months.

The post-filter, an optional feature on whole house water filtration systems, further traps remaining sediment and organic particles that were not caught earlier.

Filtration Tanks

Replace the water filtration tanks every five to 10 years or between 600,000 and 1,000,000 gallons of use.

Tanks form the core of the whole house filtration system. A paired replacement tank reduces chlorine, chloramine, and heavy metals through the upper tank and most chlorine, pesticides, herbicides, and VOCs in the lower tank.

UV Filter (Lamp)

Replace the ultraviolet (UV) lamp on a whole home filtration system when the current lamp is no longer working.

Unlike the other filters, which are physical sieves, the UV filter is a light source that kills nearly 100-percent of viruses and bacteria like E.coli, giardia, and cryptosporidium. It is an optional feature on filtration systems. Bulb life is estimated to be about one year.

Salt-Free Water Softener Filtration Tank

Replace the salt-free water softener (or water conditioner) about every 6 years on a whole home water filtration system.

The salt-free water softener is an optional feature for homes that have water with hard minerals which can build up scale and harm appliances and plumbing systems.

When It's Time to Change a Whole Home Water Filter

Various factors may require the whole house water filter to be changed more often:

Where Is the Whole Home Water Filter Located?

The whole home water filtration system will be located on your home's cold municipal water intake pipe, near the home's main water shut-off valve. This valve is usually on the inside of the house, on the perimeter. It may be located in a garage, large utility closet, storage room, or basement.

How to Change a Whole Home Water Filter

To change a whole home water pre-filter, you'll need a replacement pre-filter, a filter housing wrench, a bucket, towels, plumber's silicone grease (not sealant), and waterproof gloves.


Wear waterproof gloves when changing a whole home water pre-filter since filters. Thoroughly wash your hands with soap and hot water afterward as well.

  1. Turn off the main water shut-off valve.
  2. Turn off the water outlet valve located between the filtration system and the house. Not all systems will have this valve.
  3. Push the pressure release button, usually located on top of the filter housing.
  4. With the filter housing wrench, turn the filter housing counter-clockwise to remove it. Remember that the housing is pointed down to the floor, so imagine that you are laying on the floor and looking upward.
  5. Remove the filter from the housing.
  6. Pour the water in the housing into a drain or bucket.
  7. Clean the inside of the housing with warm soapy water. Rinse and dry the housing.
  8. Place the replacement pre-filter in the housing.
  9. Run a thin layer of the plumber's silicone grease on the housing's rubber gasket.
  10. Screw the housing back in place by hand, then tighten it with the filter housing wrench.
  11. Turn on the water inlet and outlet valves.
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  1. Choosing Home Water Filters & Other Water Treatment Systems. Centers for Disease Control and Prevention