All water filters use carbon filtration, ion exchange or reverse osmosis. Most refrigerators have filters that use carbon filtration. This means water passes through carbon granuales to remove any impurities. Ion exchange filters work very much the same way, except they contain resin beads. In a reverse osmosis filter, water is forced through a thin membrane.

The design of  each type of water filter’s housing or case varies, but the process is the same. However, not all filter types fit all refrigerator models. Check the owner’s manual for the water filter that’s specific to your appliance. 

Locate where the twist-on fridge filter is. Sometimes it’s in a drawer or inside in the back. Here’s how to change a water filter in the fridge that uses a twist-on case. Always consult the owner’s manual for specific instructions.

• Place a dish towel underneath to catch any drips or water.
• Twist the filter housing counterclockwise with a 1/4 turn. 
• Pull the filter straight out. Be gentle but firm.
• Remove the old water filter inside the filter housing and place in a new filter.
• Push the new filter straight into the housing. 
• Turn it 1/4 turn clockwise or until it locks into position.

A push-in filter has a spring that holds it in place. Here’s how to change a water filter in the fridge that uses a push-in case. Always consult the owner’s manual for specific instructions.

• Place a towel underneath to catch any drips or water.
• Release the spring that holds the filter in place. This can mean pushing a button or pushing in the filter itself. 
• Take the filter case out of the unit.
• Take the cap off the old water filter. 
• Put the cap on the replacement filter.
• Insert and push the new filter back into the housing until it locks.

Replacing some refrigerator water filters can require tools, skill and time. These include ones that are installed in the bottom of the refrigerator or in the water line behind the fridge. Consider getting professional help to change these types of filters. 

Below are the general steps for changing an ice or water filter installed in the refrigerator's water line. Consult the owner’s manual for specific instructions.

• Pull the refrigerator out and unplug it.
• Place a bucket or towel under the inline water filter.
• Take the filter housing from its case. 
• Disconnect the filter from the water line. Depending on the style, you may have to use pliers or your fingers. 
• Pull the supply lines from the filter and remove any fittings.
• Screw or connect the new filter into the fittings.  
• Reconnect the water supply lines to the supply valve.
• Turn on water. Flush the filter according to the filter’s manufacturer’s instructions and the appliance manual. 
• Turn off the water supply. 
• Connect the fridge water line to the new filter’s outlet side.
• Turn water valve back on.
• Check for any leaks.

A good rule of thumb about how often to change a fridge water filter is every six months. Smart fridges may have a touchscreen panel with a light that flashes when it’s time to change your filter. The current filter itself can also list the date it needs to be changed. When it’s past time to change your fridge’s water filter, you may notice that the taste of the ice or water has changed or it smells funny. In some cases, water may flow slower from the dispenser.