Sub-Zero filters, and a smell.
A Sub-Zero holds two consumables and they do different jobs. The air purification cartridge scrubs the air of ethylene and odor every 20 minutes and is due at about 365 days. The water filter runs on two triggers, whichever arrives first. And if the cabinet actually smells, Sub-Zero’s own answer to that question never mentions either cartridge, which is the most useful sentence on this page.
On This Page
The air cartridge, and what it is for.
For the air, and what the produce gives off into it. Many fresh foods emit ethylene, a naturally occurring compound that hastens ripening and spoilage, and Sub-Zero says the system scrubs the air of ethylene and odor every 20 minutes, on technology it describes as developed by NASA. It works on the air the cabinet holds, but it does not reach the cause of a smell.
Sub-Zero is also careful about what it does not claim. Its own wording is that the purifier is intended to greatly reduce, not necessarily completely kill, bacteria. We are not going to improve on that sentence, and anyone selling you more than it is going past the maker.
The icon tells you where you stand, in three states. No icon means the system is off. An icon sitting steady means it is running. An icon flashing means the cartridge is due, which happens after about 365 days or if the cartridge bulb burns out. A Designer goes one better and shows the life remaining as a percentage, counting down from full. Sub-Zero also says that using the air filter is not required: no harm is done to the unit if it is not replaced or not used.
Which Units Have It
Sub-Zero lists both sides of this, and the second column is the one that saves an afternoon of looking for a cartridge that was never fitted.
| Listed as having it | Listed as not |
|---|---|
| Classic, in the BI and CL lines | All freezer units |
| Designer column and tall, in IT, IC, DET and DEC | All wine storage units |
| Drawer models ID-30RP and ID-36RP | The earlier 600 Series |
| Professional PRO4850 and PRO3650 | The earlier 700 Series |
Those letters are the same ones that identify the line itself, which is the practical reason to know them. Which series is which, and what it was called before.
The water filter, and its two triggers.
The filter icon appears on either of two conditions, whichever arrives first: the volume of water the filter is rated for has passed through it, or approximately one year has gone by. Volume and time, and a household that drinks from the dispenser all summer will reach the first one long before the second.
The icon is specific enough to recognize without a manual: four drops of water passing through a horizontal sheet of paper, shown between the two temperatures in the control panel display. Once the new cartridge is in, the monitor has to be told. On a Classic that means pressing and holding the white filter reset button for five seconds, and Sub-Zero puts that button to the left of the water filter on the front of the condenser cover, which on that line is at the top of the cabinet.
| Air purification cartridge | Water filter | |
|---|---|---|
| What it is for | Scrubbing the air of ethylene and odor every 20 minutes | The water going to the dispenser and the ice maker |
| Replace after | About 365 days, or if the cartridge bulb burns out | The rated volume filtering through, or about one year |
| How you are told | The icon flashes; a Designer shows the life left as a percentage | An icon of four drops passing through a sheet of paper |
| Reset | — | Hold the white button left of the filter for five seconds |
| Shelf life, unused | None, as long as it is not plugged into a unit | None, as long as no water has been run through it |
| What it is based on | Technology Sub-Zero describes as developed by NASA | — |
The “Replace after” row is worth a sentence of its own. If the filter is dying early and often, the water is the suspect rather than the filter, and in this valley that is not a long investigation. What the water does across the valley.
Neither one has a shelf life.
This sounds like it should be bad news, and it is not. Sub-Zero states that its air purification cartridges and water filters do not have a shelf life: as long as water has not been run through a water filter and the air cartridge has not been plugged into a unit, there is no expiration date and no use-by date.
So buying the spare with the replacement is not a gamble. The cartridge in the drawer is the same cartridge in a year, which is the sensible way to own a machine whose consumables announce themselves at an inconvenient moment.
The smell neither cartridge fixes.
Sub-Zero publishes an answer for odor inside a refrigerator, and the striking thing about it is an absence: the air purification cartridge is not in it. Not as a first step, not as a footnote. What it lists instead, in its own order, is this.
| What Sub-Zero lists | What it comes down to |
|---|---|
| High refrigerator or freezer temperatures | A temperature not held |
| A door seal cracked or torn | A door not sealing |
| Service error indicators on the control panel | The machine already telling you |
| Standing water or other foreign matter in the drain pan | Water not leaving |
| Clogged drain tubes, or standing water on the refrigerator floor | Water not leaving |
| Extended power loss | A temperature not held, in the past |
Four of those six come down to two things: water that is not leaving, and a temperature that was not held. Which is why a smell and a wet floor can arrive in the same week, and why the useful first move is to look at the drain rather than at the shopping list. Where that water is coming from.
Its own steps run in order too: sanitize before storing food again, clean recent spills, clean the drain tube, clean the shelving and the door gasket, and cover food. The drain tube and pan are the owner’s only on some series: which drain is yours. For an extreme case it goes further, to a thorough clean of the interior including the drain pan, tubes, gaskets and all crevices using warm water, dish detergent and a capful of bleach, then the doors blocked open with a fan running for several days, and crumpled newspaper, charcoal briquettes, activated charcoal or fresh coffee beans changed daily. Past that it says the evaporator needs a technician, and past that, the unit out of the opening.
That last escalation is the honest reason a smell is sometimes not a cheap visit. Everything up to the gasket is a Saturday. The evaporator is behind a panel, and the opening is a cabinetry job. What the $119 visit consists of.
Questions
The air filter icon is flashing. What does that mean?
That the cartridge is due. Sub-Zero gives the icon three states: absent means the system is off, present and steady means it is running, and present and flashing means replace the cartridge. It starts flashing after about 365 days, or if the cartridge bulb burns out. On a Designer the display goes further and shows the remaining life as a percentage.
What does the air purification system actually do?
It scrubs the air of ethylene and odor every 20 minutes, using technology Sub-Zero describes as developed by NASA. Ethylene is the compound that hastens ripening and spoilage, so the system is aimed at how long food lasts, but it does not reach the cause of a smell. Sub-Zero is careful about the rest: it says the purifier is intended to greatly reduce, not necessarily completely kill, bacteria.
Does my unit have one?
Sub-Zero lists it on Classic in the BI and CL lines, on Designer column and tall models in the IT, IC, DET and DEC lines, on the ID-30RP and ID-36RP drawer models, and on the PRO4850 and PRO3650. It lists it as absent from all freezer units, all wine storage units, and the earlier 600 and 700 Series. If you own a 600 and cannot find the cartridge, that is why.
When does the water filter need changing?
On either of two triggers, and whichever arrives first. Sub-Zero’s answer is that the icon appears when either the volume of water the filter is rated for has filtered through, or approximately one year passes. The icon itself is four drops of water passing through a horizontal sheet of paper, shown between the temperatures in the control panel display.
How do I reset the filter indicator?
On a Classic, press and hold the white filter reset button for five seconds. Sub-Zero places that button to the left of the water filter, on the front of the condenser cover, which is at the top of the cabinet on that line.
Will a new cartridge fix a bad smell?
Not on its own, and it is worth knowing why. Sub-Zero’s own answer on odor inside a refrigerator never mentions the air purification cartridge at all. It lists high temperatures, a cracked or torn door seal, service indicators on the control panel, standing water or matter in the drain pan, clogged drain tubes or water on the refrigerator floor, and extended power loss. Those are the causes it names, and a fresh cartridge will not reach any of them.
Sources
- Sub-Zero, how to use the air purification system: the scrub of ethylene and odor every 20 minutes, ethylene as a naturally occurring compound that hastens ripening and spoilage, technology developed by NASA, the purifier intended to greatly reduce rather than necessarily completely kill bacteria, the three icon states, replacement after about 365 days or a burned-out cartridge bulb, the percentage of life remaining on Designer units, using the air filter not being required, and the list of lines that have the system and those that do not.
- Sub-Zero, air purification cartridge and water filter shelf life: that they do not have one, and that there is no expiration or use-by date as long as no water has been run through the filter and the air cartridge has not been plugged into a unit.
- Sub-Zero, Classic Series (BI) water filter replacement indicator: the icon of four drops of water passing through a horizontal sheet of paper between the temperatures, the two replacement triggers of rated volume or approximately one year, and the white filter reset button to the left of the water filter on the front of the condenser cover, held for five seconds.
- Sub-Zero, odor inside a refrigerator: the six causes in its own order, the ordered troubleshooting steps, the extreme-odor clean using warm water, dish detergent and a capful of bleach, the doors blocked open with a fan for several days, the newspaper, charcoal briquettes, activated charcoal or fresh coffee beans changed daily, and the escalation to evaporator cleaning and removal from the opening. The air purification cartridge does not appear in that answer.
- Sub-Zero, undercounter ice maker UC-15I water filter: replacement every six months, after a prolonged shutdown, or when the red REPLACE FILTER light comes on, which is the interval for that filter rather than for a refrigerator cartridge.
Written from these sources and reviewed on (checked again ) by Aphelion Appliance Repair, Phoenix. Each figure belongs to the line or the filter named with it, and a figure for one cartridge is not a figure for another. Nothing here replaces the maker’s own instructions.
Read Next
- Which Sub-Zero series do you have?Classic was Built-In, Designer was Integrated, and the tag decides.
- Water on the floor, under the refrigeratorA pint is the threshold, and the series decides whether the drain is yours.
- What hard water does to the ice makerHardness by city, and the cleaning the makers actually specify.
- Water dispenser not working, slow or dryAir after a new filter, a lock, Sabbath Mode, a clogged filter or low pressure: Sub-Zero’s and Monogram’s own checks, down to how long to hold the button.
Smell still there?
Send the model and serial from the tag, and what you have already cleaned. We answer every day, 7am–6pm.