Refrigerator Repair
Replacing the Sub-Zero Air Purification Cartridge 7042798
To replace a Sub-Zero air purification cartridge, order genuine part 7042798, open its housing in the fresh-food section, swap the spent cartridge for the new one and press Refresh on the control. Here is each step, plus the warranty and disposal details.
Written byElena Sandoval
- Role
- Refrigeration technician — cabinet, door and seal work
- In the trade
- 24 years in the trade
- Certification
- EPA 608 certified
To replace the air purification cartridge in a Sub-Zero refrigerator, order part 7042798, open the small housing inside the fresh-food compartment, slide the spent cartridge out, push the new one in until it sits fully home, close the cover and press Refresh when the control asks. Most owners finish in a few minutes without tools. It is worth doing on time, because that cartridge is what stops ripening fruit from hurrying along everything stored next to it. In a Westwood or Venice kitchen where a bag of avocados goes straight onto the top shelf to slow down, a tired cartridge shows up as limp herbs and lettuce that turns early.
What the cartridge does and which number to order
This cartridge is the only air filter a Sub-Zero refrigerator carries, and it fits every model that was built with an air purification system. The current part number is 7042798. If your manual, a spare box in the garage or the label on the old cartridge says 7007067, skip the search for that number: 7042798 directly replaces it, so the newer part is the one to buy.
The cartridge works on the air in the compartment, not on your water. Every 20 minutes it strips ethylene and odors out of the cabinet, using technology Sub-Zero says grew out of NASA research. Ethylene is the gas fruit and some vegetables release as they ripen, and it speeds up the ripening of whatever sits close by, so a working cartridge buys your produce time. A small mercury lamp is built into the assembly, which is why the spent one needs some care when it leaves the house.
If you look through the fresh-food section and find no housing at all, the unit was most likely made without the system; the cartridge is not an add-on for every cabinet. Our Sub-Zero units by series page can help you work out which family you own.
Swapping the cartridge, step by step
- Check that the box in your hand reads 7042798 before you open anything.
- Clear the top shelf so you can see and reach the housing. On full-size built-ins it normally sits high in the refrigerator compartment toward the back wall; the use and care guide for your series marks the exact spot.
- Release the cover by hand. It is held by a tab or clip, and prying it with a screwdriver risks cracking the plastic.
- Draw the old cartridge straight out, holding it by the body, and lay it somewhere it cannot roll off the counter.
- Unwrap the new cartridge, take off any packing material, and slide it in the same way the old one came out until it stops.
- Close the cover and make sure it latches flush.
- Reset the reminder on the control, described in the next section.
If the new one refuses to go in the way the old one came out, compare the two side by side instead of forcing it. The reminder runs on a timer, so it will count down a full year whether or not a badly seated cartridge is actually doing anything.
Clearing the reminder on the control
On Classic (CL) and Designer (DET, DEC) models with touch controls, the display shows Snooze/Refresh when either the water filter or the air cartridge has reached the end of its life. Snooze pushes the prompt back 24 hours, which helps if the replacement is still in the mail. Once the new cartridge is in, choose Refresh and that cartridge’s cycle begins again for roughly a year. The same prompt serves both consumables, so read the screen to confirm which one it means before you change the wrong part.
Older Classic (BI) units use a different control. Don’t carry the water filter routine over to them: pressing the white reset button left of the filter five times within seven seconds is how Sub-Zero switches off the water filter life monitor once the filter is removed or bypassed with plug 7011209. It is not an air cartridge reset. For a BI, follow the use and care guide written for that unit.
Air cartridge or water filter: keep them straight
Owners mix the two up all the time, partly because one prompt covers both. Here is how they differ on the models that have each.
| Air purification cartridge | Twist-in water filter | |
|---|---|---|
| Part number | 7042798, replacing 7007067 | 4204490, interchangeable with 9030868 |
| What it treats | ethylene and odor in the cabinet air | water headed for the dispenser and ice |
| When to change | about once a year | 750 gallons (2,839 L) or 12 months on CL, DET and DEC |
| Warranty | not covered | not covered |
The twist-in filter fits Classic (BI, CL), Designer (DEC, DET), 648PRO, PRO3650 and PRO4850 models. Besides the indicator and the calendar, change it early if water pressure drops or cubes come out hollow.
Plenty of Sub-Zero units carry no internal water filter at all. That list includes the UC-24 undercounter models, DEU undercounter refrigeration, ID drawers, the 500 Series and 600 Series, and wine storage other than the IW-30CI. If your kitchen runs on undercounter Sub-Zero units, there may be no water cartridge anywhere in the cabinet to worry about.
What the warranty covers here, and what it does not
Sub-Zero’s residential limited warranty leaves out replacement air purification cartridges and replacement water filters, so a new 7042798 is always a purchase, never a claim. That changes how to think about genuine versus aftermarket. You are not guarding your coverage by buying genuine; you are buying the cartridge designed for that housing and the lamp it was built around. Listings that say a cartridge ‘fits’ or is ‘compatible with’ your refrigerator are not the numbered Sub-Zero part, and nothing on the listing tells you what lamp or media sits inside.
Coverage does matter for everything else in the cabinet, and it turns on the model and serial number. The serial tag gives you both. Owners of a Classic (BI, CL), 600 Series or 500 Series over-and-under unit should open the refrigerator door and look up by the top hinge. A side-by-side hides its tag behind the freezer door instead, while a Classic French-door model puts it on the inner face of the left door. The tag also prints the date the unit was built, a useful starting point if you are trying to work out whether a fault might still be covered.
The model number itself spells out the build. Take DET3050CIID/R: by Sub-Zero’s own key it is a 30-inch Designer that pairs a refrigerator with a freezer, makes ice, dispenses from inside the cabinet and swings on the right, which is exactly the detail a parts counter asks for. Units approved for outdoor use by model and serial number fall under a separate outdoor limited warranty: a full year on all parts and labor, plus a full five years on the sealed system.
Getting rid of the old one in Los Angeles
The mercury lamp means the spent cartridge does not belong in the black bin. California keeps mercury-bearing lamps out of household trash, so take it to a household hazardous waste drop-off; both the City of Los Angeles and LA County run collection sites and events that homeowners from Woodland Hills to Playa Vista can use. Packing it in the new cartridge’s box keeps the lamp from breaking in the car.
When the real complaint is a warm refrigerator
A fresh cartridge will not move the temperature by a single degree. It cleans air and has no role in cooling. If the fresh-food side feels warm while the freezer still holds, the usual causes are airflow and defrost: an evaporator fan that has quit, a coil buried in frost, or a sensor reporting the wrong number. A condenser working flat out through a Valley heat wave is another, and our guide to a condenser running non-stop in Los Angeles heat walks through it.
Typical ranges, with the firm price given only after diagnosis: an evaporator or condenser fan motor runs $310–$680, a defrost heater, thermostat or sensor $290–$670, an electronic control board $440–$970, and compressor or sealed-system work $1,300–$3,030. The visit itself is $89; it covers the technician’s trip and finding the fault, and we deduct it from the total when you go ahead with the repair. Call (310) 919-2538 or use the booking button on this page.
Follow-up questions
Is Sub-Zero part 7042798 the same as 7007067?
Yes, 7042798 is the direct replacement for the older 7007067, so order the newer number even if your manual or the old cartridge shows 7007067. It fits every Sub-Zero model built with an air purification system.
How often should the Sub-Zero air purification cartridge be changed?
Plan on roughly once a year. On Classic (CL) and Designer (DET, DEC) touch controls the display shows Snooze/Refresh when it is due; Snooze holds the reminder off for 24 hours, and pressing Refresh after the swap starts a new cycle of about a year.
Can the old cartridge go in the household trash?
No, because it contains a small mercury lamp that has to be disposed of under the disposal laws. In Los Angeles that means a household hazardous waste drop-off rather than the black trash bin. Carry it there in a box so the lamp cannot crack on the way.
Will a new cartridge fix a Sub-Zero refrigerator that is not cooling?
No, the cartridge only cleans the air and plays no part in cooling. A warm fresh-food section, especially while the freezer still holds, usually points to a fan, a frosted coil, a sensor or the condenser. Diagnosis starts with an $89 visit that is credited toward the repair once you approve it.
Does the Sub-Zero warranty cover a replacement air purification cartridge?
No, Sub-Zero's residential limited warranty excludes replacement air purification cartridges and replacement water filters alike. Each new 7042798 is a normal purchase, so buying the genuine part is about fit and function rather than protecting coverage.