Fridge Water Filters
Fridge Water Filters: How They Work and When to Replace
A fridge water filter is a cartridge of activated carbon that traps contaminants in your tap water before it reaches the dispenser and ice maker. Replace it roughly every 6 months because the carbon stops adsorbing impurities once it is full. Most filters twist or push into place without tools.
Type your appliance model number (e.g. RF23R5201SR) or an old part code (e.g. DA29-00020B).
Not sure where to find it? How to find your model number →
Compatible fridge water filters
How does a fridge water filter actually work?
A fridge water filter passes tap water through an activated carbon block with very fine pores. The carbon adsorbs contaminants such as chlorine, sediment and certain metals as water flows past, so the dispenser and ice maker deliver filtered water. The cartridge sits inline on the fridge's internal water supply.
Most fridge filters use the same core design:
- An outer housing that seals into the fridge's water line
- An activated carbon block, which has a very large internal surface area
- Adsorption, where contaminants stick to the carbon as water passes through
The filter does not boil or chemically treat the water. It physically traps particles and adsorbs dissolved substances. Once the carbon is saturated, water simply passes through without being cleaned, which is why replacement matters more than cleaning.
Why should you replace a fridge filter every 6 months?
Replace a fridge water filter every 6 months because the activated carbon has a finite capacity. Once it is full, it stops reducing contaminants and can let trapped material back into the water. Many manufacturers also rate filters to about 300 gallons, whichever comes first, depending on your water quality.
Two limits decide when a filter is spent:
| Limit | Typical figure | Notes |
|---|---|---|
| Time | 6 months | Use this even if volume is low |
| Volume | Around 300 gallons | Reach this sooner with heavy use |
Hard water and heavy dispenser use shorten filter life. Signs it is overdue include slower water flow, a return of chlorine taste or smell, and cloudier ice. A clogged filter can also strain the dispenser, so replacing on schedule protects the appliance as well as the water.
Compatible vs genuine OEM filters: which is safe?
Both compatible and genuine OEM filters can be safe if they are certified. OEM filters are made by the appliance brand for a guaranteed fit. Compatible filters are made by other firms to fit the same models at lower cost. Check for NSF/ANSI certification and confirm the exact part number before buying.
The key is independent certification, not the brand name:
- NSF/ANSI 42 covers aesthetic reduction such as chlorine taste and odour
- NSF/ANSI 53 covers health-related contaminants such as lead and mercury
What to check for a safe, correct fit:
- The filter lists your exact OEM part number as a replacement
- The fitting type matches (twist-in, push-in or in-door cassette)
- The seal and length match the original so it locks fully home
A certified compatible filter that lists your part number and matches the fitting will perform to the standard it is certified for.
How do I find the right fridge filter for my model?
Find the right fridge filter by matching your appliance model number or the existing filter's part number. The model number is on a rating plate inside the fridge, often on a side wall or near the salad drawers. The filter part number is usually printed on the old cartridge itself.
Two reliable routes to the correct filter:
1. Read the part number off the old filter. Brands print codes such as DA29-00020B or EDR1RXD1 directly on the cartridge.
2. Find the appliance model number on the rating plate, then look up the matching filter.
The rating plate is typically inside the fridge compartment, on a side wall, the ceiling, or near the salad drawers. Once you have either number, search it to confirm the certified filter that fits. Never guess from the fridge brand alone, as one brand uses several filter types across its range.
Is a filter subscription worth it?
A filter subscription is worth it if you struggle to remember the 6-month replacement schedule. It sends the correct, certified filter for your model to your door on time, so the carbon never runs past its useful life. You keep filtered water and ice without tracking dates or reordering each time.
A subscription suits households that want the schedule handled for them:
- The correct filter for your registered model arrives automatically
- Delivery timing matches the 6-month change interval
- You avoid running on a spent filter that no longer cleans the water
The main benefit is removing the admin so the filter is always changed on time, which is the single thing that keeps the water quality consistent.
Frequently asked
What happens if I never change my fridge water filter?
The activated carbon saturates and stops reducing contaminants, so unfiltered water passes through. Flow can slow as the filter clogs, taste and odour return, and trapped material may release back into the water. The dispenser and ice maker also work harder against a blocked cartridge.
Do I need to turn off the water to change a fridge filter?
Usually no. Most in-fridge filters have a self-sealing valve that stops the flow when you remove the cartridge, so you can swap it without shutting off the supply. Check your manual, as some external or inline filters need the supply isolated first.
Are NSF-certified compatible filters as good as OEM?
For the contaminants they are certified against, yes. NSF/ANSI 42 and 53 certification verifies performance independently of brand. A certified compatible filter that lists your exact part number and matches the fitting will perform to that standard. The difference is cost and brand guarantee of fit.
How long should I flush a new fridge filter?
Run water through in short bursts until it runs clear and stops sputtering, often a few litres in total. This clears loose carbon dust and trapped air. Discard the first batch of ice as well, since it may contain specks from the new carbon block.