Table of Contents:
Water Filter vs Air Filter vs Ice Maker Filter: What Is the Difference?
What Are the Signs That a Refrigerator Air Filter Needs to Be Replaced?
How Often Should I Replace My Refrigerator Water Filter?
Does a Refrigerator Ice Maker Use the Same Water Filter as the Water Dispenser?
A Simple Maintenance Timeline for the Three Filtration Functions
Conclusion
FAQs
Most people know their refrigerator has a water filter. Fewer know it may also have an air filter. Almost nobody thinks about the ice maker as having filtration needs of its own — until the ice starts tasting like last week's leftovers.
One clarification before going further, because the headline invites a misreading. "Three filters" describes three maintenance functions, not three cartridges sitting in every refrigerator. A French door model might hold an air filter and a water filter, with the ice maker drawing from that same filtered water supply — two cartridges covering three jobs. A standalone undercounter ice maker, meanwhile, has its own dedicated cartridge and nothing to do with the refrigerator at all. The count depends entirely on how the appliance was designed.
Water Filter vs Air Filter vs Ice Maker Filter: What Is the Difference?
They treat different media for different reasons, and confusing them leads to the wrong maintenance on the wrong schedule.
The refrigerator air filter treats air circulating inside the fresh-food compartment. Its job is odor control — keeping cut onion from transferring to butter, and leftovers from announcing themselves every time the door opens. It touches no water and carries no drinking-water performance claim.
The refrigerator water filter treats water going to the dispenser and, on most models, to the ice maker as well. This is the cartridge with contaminant-reduction claims attached, tested against standards like NSF/ANSI 42 for aesthetic effects and NSF/ANSI 53 for health-related contaminants.
A dedicated ice maker filter is a separate cartridge found on certain standalone ice-making systems. Same general technology as a refrigerator water filter, different housing, and — importantly — a completely independent replacement schedule.
Both the air filter and the water filter rely on activated carbon, which is why they get conflated. The mechanism is genuinely similar. EPA describes granular activated carbon as a porous adsorption medium with extremely high internal surface area, manufactured from raw materials including coconut shells, and notes that its treatment capacity varies with the properties of the carbon itself. The medium adsorbs onto empty pore space until that space runs out — then it has to be replaced or regenerated.
That last sentence applies to both filters. What differs is what's being adsorbed and how fast the capacity gets used up.
For applicable models, GlacierFresh's LT120F-compatible air filter (GFA-002) handles the odor-control function, while the GF1000P water filter supplies filtered water for compatible LG drinking-water and ice-making systems.
What Are the Signs That a Refrigerator Air Filter Needs to Be Replaced?
Three cues, in roughly the order people notice them:
Food odors that stop clearing on their own. The most reliable early signal. A working carbon filter keeps strong smells from spreading between compartments; when that stops happening, the carbon is saturated.
A change-filter indicator on the control panel. Convenient but time-based, not condition-based.
Odor that returns quickly after a deep clean. If you empty and wipe the interior and the smell is back within a day or two, cleaning isn't the problem.
Replacement intervals vary by refrigerator design. LG's guidance for applicable Fresh Air Filter models centers on approximately six months. GlacierFresh's LT120F-compatible cartridge is specified for replacement every three to six months and uses a three-layer construction — a non-woven cloth layer for larger particles, activated carbon fiber for odor adsorption, and an activated carbon sponge for dust holding.
The range rather than a fixed number is deliberate. A refrigerator holding a lot of aromatic food loads its air filter faster than one holding mostly sealed containers.
How Often Should I Replace My Refrigerator Water Filter?
Six months is the common manufacturer interval, and rated gallon capacity is the second half of the answer — whichever arrives first.
Time and volume both matter because they describe different failure paths. Carbon capacity is consumed by the volume of water passing through it. A household of five with a hard-working ice maker can reach a 200-gallon rating in three months; one person in a studio apartment may not reach it in nine. Meanwhile, NDSU Extension notes that a carbon filter sitting unused for more than five days can become a food source for bacteria if it is already loaded with organic material, which is why a calendar limit exists alongside the volume limit.
Three symptoms tend to cluster around the replacement point:
- Reduced flow at the dispenser. NDSU advises paying attention to any reduction in pressure at the tap as an indication the filter is saturated with particles, and recommends changing the filter every three to six months of use, or sooner if flow drops or unpleasant taste and odor return.
- Taste or odor breakthrough. Chlorine taste coming back means the carbon has stopped adsorbing it.
- The filter indicator. Useful as a prompt, but it estimates from assumed average flow rather than measuring the cartridge.
GlacierFresh's GF1000P lists a six-month / 200-gallon service interval on its current product page. It is a replacement for LG LT1000P, LT1000PC, LT1000PCS and ADQ747935 filter systems, IAPMO-certified to NSF 53, built on coconut-shell activated carbon with a 0.5 µm pore size, and rated to remove 97.9% of chlorine. For a fuller treatment of the timing question, see our guide to how often to change a refrigerator water filter.
Does a Refrigerator Ice Maker Use the Same Water Filter as the Water Dispenser?
On most built-in refrigerators, yes — one cartridge feeds both. The dispenser and the automatic ice maker branch off the same supply line downstream of the filter, which is why ice quality tracks water quality on these models and why a clogged cartridge shows up as smaller cubes and slower production.
On compatible LG systems, a single GF1000P therefore covers drinking water and ice together. There is no separate ice filter to find, and no separate schedule to track.
Standalone units work differently. Sub-Zero's undercounter ice maker UC-15I ships with a water filter installed in the unit, located on the bottom-left side behind the ice maker door. Sub-Zero specifies replacement every six months, after a prolonged shutdown, or when the red REPLACE FILTER light illuminates — and the reset is a dedicated action, pressing the CLEAN key for six seconds to clear the counter and light.
Two details from that procedure generalize usefully to any ice-maker cartridge. The blue cap has to come off the replacement filter before installation. And rather than flushing water through, Sub-Zero instructs users to discard the first batch of ice after replacing the filter — the ice equivalent of flushing the line.
GlacierFresh's GF-34 is a compatible replacement for Sub-Zero 7012333, 7042803 and the UC-15I family, using carbon block media at 0.5 µm and rated for up to six months or 200 gallons.
A Simple Maintenance Timeline for the Three Filtration Functions
| Function | What it treats | Typical interval | Replacement trigger |
|---|---|---|---|
| Air filtration | Air inside the fresh-food compartment | Per manufacturer; LG guidance for applicable Fresh Air Filter models centers on ~6 months. GlacierFresh LT120F-compatible: every 3–6 months | Persistent food odors, or the change-filter indicator |
| Refrigerator water filtration | Dispenser water and, on most models, ice | 6 months or rated gallons, whichever comes first. GF1000P: 6 months / 200 gallons | Reduced flow, taste or odor breakthrough, or filter indicator |
| Dedicated ice-maker filtration | Water to a standalone ice maker only | The ice maker's own schedule. Sub-Zero UC-15I: every 6 months, after prolonged shutdown, or at the REPLACE FILTER light. GF-34: up to 6 months / 200 gallons | REPLACE FILTER indicator, or ice taste and clarity changes |
The scheduling error worth avoiding: treating these as one job because they happen to land near the same date. They are three independent clocks. An air filter runs on odor load, a refrigerator water filter runs on gallons and months, and a dedicated ice-maker cartridge runs on its own counter, which is why Sub-Zero gives the UC-15I a separate reset key rather than tying it to anything else in the kitchen.
Running all three on one date is fine as a convenience. Assuming one replacement covers all three is not. A general water filter maintenance checklist helps keep the intervals from drifting into each other.
Air, drinking water and ice solve different problems with different media on different schedules. The air filter manages odor inside the cabinet. The water filter carries the contaminant-reduction claims and feeds the dispenser — and on most refrigerators, the ice maker along with it. A dedicated ice-maker cartridge exists only on certain standalone units, and when it does exist, it keeps its own counter.
The useful question isn't how many filters a refrigerator contains. It's which functions share a cartridge and which have a schedule of their own. Answer that for your specific model and the maintenance calendar writes itself: the LT120F-compatible air filter, the GF1000P water filter and the GF-34 ice-maker filter cover the three roles independently. Browse the full range of refrigerator water filters to match your model number.
FAQs
Do all refrigerators have an air filter?
No. Air filters appear on certain model lines, commonly French door designs, and not across the board. Check the owner's manual or look for a small cartridge housing inside the fresh-food compartment. No housing means no air filter to maintain.
How often should I replace a refrigerator air filter?
Follow the refrigerator manufacturer's interval. LG's guidance for applicable Fresh Air Filter models centers on approximately six months, and GlacierFresh's LT120F-compatible cartridge is specified for every three to six months. Persistent food odors are the practical signal to replace it early.
Does changing the refrigerator water filter improve ice quality?
On models where the ice maker draws from the filtered line, yes. A saturated cartridge restricts flow, which tends to produce smaller or partially formed cubes, and taste or odor breakthrough carries into the ice. After a replacement, discard the first batch — Sub-Zero specifies exactly that for the UC-15I, and it is sound practice on any ice maker.
