How to read a fridge water filter reference code

A fridge water filter reference is a code the manufacturer assigns to one specific cartridge housing and one specific filtration standard. It is printed directly on the cartridge, and it is the single most reliable way to buy the correct replacement, more reliable than searching by your fridge's model number alone.

The parts of most codes

Part	Example	What it tells you
Manufacturer prefix	DA29, ADQ, SBS	Which brand and which internal parts family the cartridge belongs to
A number, where present	00020B, 73613401, 002	Distinguishes between several housings sold by the same brand
An alternate retail name	HAF-CIN/EXP, LT800P	A second name the same physical cartridge is sold under, often on the retail box rather than the plastic itself

Why the code matters more than the fridge's model number

Manufacturers change the internal filter housing every few years, but they keep selling and supporting older fridges for a long time afterwards. That means a single brand can have several completely incompatible filter systems on the market at once. Samsung is the clearest example: a fridge bought a decade ago and one bought this year can both be called a Samsung French door fridge, yet they can take entirely different cartridges. The fridge's model number tells you which appliance you own, but only the filter reference code tells you which cartridge fits it.

What to do if you cannot find the code

Open the filter door, usually inside the fresh food compartment or at the base grille, and read the reference printed on the old cartridge before you dispose of it.
Check the fridge's rating plate, usually on the side wall or ceiling of the fresh food compartment, then search that model number using the tool on our homepage.
Check the user manual, which usually lists water filters under a consumables or spare parts section.
If there is no filter door anywhere inside the fridge, check behind or underneath it for an external cartridge on the water supply pipe.

Once you have the code, check it against the brand page for your fridge on this site, which lists the exact fitment, fitting position and change interval for that reference.

Step by step procedure for reading the code accurately

Remove the cartridge only when you can see how it is locked in place. Most internal cartridges release with a quarter turn, usually about 90 degrees, or by pressing a small eject button. Do not use pliers on the plastic head, because the head can ovalise and make the printed code harder to read.

Dry the outside of the old filter with kitchen paper before reading it. Condensation and fine limescale can hide small suffixes such as a final letter or an export marking. Use a phone torch at a shallow angle, about 30 to 45 degrees to the label, because embossed or pale grey printing is often easier to see with side light than with direct light.

Read the full text in three passes. First, copy every large code printed on the cartridge body. Second, copy any smaller code near the barcode or QR marking. Third, inspect the end cap and neck of the cartridge, because some moulded codes are placed close to the locking lugs. Photograph the cartridge from at least 3 sides before throwing it away. A clear photo taken from 20 to 30 cm away is usually enough for later checking.

Write the code exactly as printed, including slashes, hyphens, spaces, letters and final suffixes.
Check whether the same cartridge shows more than one name, one may be a service code and one may be a retail code.
Ignore dates, batch numbers and certification marks when choosing the replacement, unless they are next to the actual filter reference.
If the fridge has an external inline filter, measure the pipe size before ordering any push fit replacement.

If no readable marking remains, identify the appliance first, then cross check the filter from the appliance model. The appliance model procedure is covered separately at how to identify your fridge model.

Equipment, measurements and figures to record

You do not need specialist tools, but a few simple checks prevent most wrong orders. Use a torch, a phone camera, kitchen paper, a ruler or tape measure, and a notepad. If the filter is external, also use a vernier caliper if available, because pipe diameters can be close by eye.

Item to record	Typical figure to check	Why it matters
Cartridge length	About 15 cm to 30 cm for many internal filters	A large mismatch means the visible code may be from packaging, not the fitted cartridge.
Cartridge diameter	About 5 cm to 8 cm for many internal filters	Helps separate slim bayonet cartridges from wider twist in designs.
Locking movement	Usually push, pull, or about a quarter turn	The same brand can use different heads with different locking shapes.
External pipe diameter	Commonly 1/4 inch or 6 mm	Inline filters and fittings must match the water pipe, not only the fridge brand.
Service life check	Often counted in months rather than only litres	A filter may be due for replacement even if the water flow still seems normal.

Record the fitting position as well as the code. Useful descriptions include upper right fresh food compartment, ceiling cartridge, lower grille, left door, and external filter behind the appliance. This is important when two possible references appear in a manual, because the fitting position often separates them.

Frequent mistakes and how to recover

The most common mistake is copying only the first block of the reference. A code can look complete after the first number, but the final letter or extra retail name may separate two different cartridges. If you have already ordered from an incomplete code, keep the old filter until the new one has been dry fitted. Do not open sealed packaging or run water through a cartridge until you have checked the locking lugs and overall shape.

Another mistake is reading a certification number as a filter code. Marks linked to performance standards, manufacturing batches or patent text are not usually ordering references. A real reference is normally printed prominently, repeated on the label, or placed near a barcode. If several codes are present, compare all of them rather than choosing the longest one.

If the new cartridge starts to enter the housing but will not lock, stop after light hand pressure. Forcing it can damage the fridge head, which is harder to replace than the cartridge. Remove it, compare the lug positions, neck diameter and end cap shape with the old filter, then recheck the complete reference. If a filter locks but water flow is poor, remove it and refit it once, making sure the protective caps have been removed and the cartridge is fully seated.

If water drips after fitting, wipe the housing dry and check again after 5 minutes. A few drops during removal can be normal, but a continuing leak suggests the cartridge is not seated, the seal is displaced, or the wrong cartridge has been fitted. For replacement timing and flushing after a correct fit, see how often to change a fridge water filter.

Special cases that need extra care

Some fridges use an internal bypass plug when no filter is fitted. Do not mistake the bypass plug for a water filter reference. A bypass plug may have moulded plastic text but usually lacks the large cartridge body and filtration label. Keep it, because it may be needed if the filter is removed during troubleshooting.

Some appliances have both an internal filter position and an external filter fitted by an installer. In that case, confirm which filter is actually in use. Trace the water pipe from the wall valve to the fridge for at least the first 50 cm. If an inline cartridge is present, its own label matters even if the fridge manual lists an internal filter.

Older filters may have faded labels or stained plastic. In that case, clean only with water and a soft cloth. Solvent cleaners can remove ink and make the code unrecoverable. If the code cannot be read, use the appliance rating plate, the fitting position and photos of the old cartridge together, then compare the result with help topics in the FAQ.