What Ink Does the Epson EcoTank ET-3843 Use?
Last Updated:Quick answer: the Epson EcoTank ET-3843 uses Epson 502 ink bottles — not cartridges. Four bottles, one per tank, and there is no XL or high-yield version, because the 502 family ships in one size only.
The wrong answer people land on for this printer is Epson 522, and it is an expensive mistake in both directions. The ET-3843 is not on Epson's 522 compatibility list. Worse, 522's black bottle is smaller than 502's — so buying 522 gets you ink that does not fit and less of it.
Part of the blame sits with retailers. Amazon's 502 listing titles read "ET-2750, 2760, 2850, 3750, 3760, 3850, 4850, and other select models" — the ET-3843 lives inside "other select models", so shoppers scanning the title conclude 502 is wrong for them and go hunting. It is not wrong. It is the only ink this printer takes.
CastleScore · October 2026
86/100 — Highly Recommended
Epson EcoTank ET-3843
| Pillar (weight) | Score | What it is based on |
|---|---|---|
| Owner ratings (28%) | 80 | 4.10★ average across 243 ratings at Amazon (4.1) |
| Expert reviews (18%) | — | No published numeric expert score we could verify. |
| Cost per page (24%) | 99 | About 0.3¢ per page blended (black + color) with our compatible 502 bottles (7,500 black / 6,000 color pages). |
| Reliability (13%) | 84 | Most-reported problems: faint or missing colours from clogged nozzles after idle periods |
| Features (12%) | 76 | Print, copy, scan, document feeder, auto two-sided printing, Wi-Fi, Ethernet. No fax, no touchscreen. |
| Value (5%) | 90 | Running cost and owner satisfaction |
Limited data: We could not find enough published expert scores for this printer, so that weight is spread across the other pillars.
Discontinued. Epson lists the ET-3843 as discontinued; its replacement, the ET-3943, takes the same 502 bottles, which are still sold.
CastleScore is Castle Ink’s own editorial rating, built from retailer star ratings, expert reviews, real cost per page and owner complaint patterns, checked October 9, 2026. It is not a customer review. See every ranked printer or how the score works.
The ink bottles, pictured
502 Bottles 4-packOur own compatible ink bottles, photographed in-house.
Epson EcoTank ET-3843 ink at a glance
| Position | Family | Part Number | Volume | Approx. Yield |
|---|---|---|---|---|
| Black | Epson 502 | T502120-S | 127 mL | 7,500 pages |
| Cyan | Epson 502 | T502220-S | 70 mL | 6,000 pages |
| Magenta | Epson 502 | T502320-S | 70 mL | 6,000 pages |
| Yellow | Epson 502 | T502420-S | 70 mL | 6,000 pages |
| 4-pack (BCMY) | Epson 502 | T502120-BCS | — | — |
| 3-pack (CMY) | Epson 502 | T502520-S | — | — |
Those volumes and yields come from Epson's own specification sheet for this printer. Worth knowing: Epson's retail ink pages only say "thousands of pages" — the actual numbers live in the spec sheet, so if you check the ink listing and find no figure, that is expected rather than a contradiction.
One ordering trap in Epson's own part numbering: the four-color pack is T502120-BCS, which begins with the black bottle's stem, while the three-color pack is T502520-S. Two packs, two unrelated-looking numbers. Read the suffix, not the stem.
What it actually costs to run
Castle Ink's compatible 502 four-pack is $38.95. Against Epson's 7,500-page rating for the black bottle on this printer, that lands at roughly 0.2 cents per black page once you apportion the black bottle's share of the pack. A cartridge-based all-in-one in the same class runs 10 to 15 cents.
Concretely: 7,500 pages of black text costs about $15 of ink here. The same 7,500 pages on an entry-level cartridge printer runs past $750. That single comparison is the entire argument for a tank printer, and you can check it against your own volumes with our ink cost calculator.
How to refill the tanks properly
- Wait until the printer tells you a tank is low. Do not top up early — once ink is mixed you cannot judge the level accurately.
- Open the tank cover and unlock the cap for the color you are filling.
- Hold the bottle upright in the port. Epson's design meters the flow and stops when the tank is full, so there is no need to squeeze.
- Fill all the way to the top line. Epson is specific about this because the reset step assumes a full tank.
- Close the cap firmly, then select the colors you refilled on the LCD and complete the on-screen reset.
Never let a tank run below its lower line. Epson warns that continuing to print below it can damage the printer — and never mix colors between ports, which means a full ink-system flush at best.
About the Epson EcoTank ET-3843
The ET-3843 is a home-office EcoTank: print, scan and copy, with an automatic document feeder, automatic two-sided printing and a 250-sheet paper cassette. There is no fax — that sits on the ET-4850 and ET-4800 in this generation.
The display is a 2.4-inch color LCD driven by physical buttons (arrow keys and OK), not a touchscreen. Connectivity is Wi-Fi 802.11 b/g/n — 2.4 GHz only, no 5 GHz — plus Wi-Fi Direct, 10/100 Ethernet and USB.
Epson has discontinued the ET-3843, and its sibling ET-3830 with it. Its replacement, the ET-3943, takes the same 502 ink — so an ET-3843 is a machine to keep running, not a dead end for supplies.
Common problems on this model
Faint or missing colors after the printer sits idle
The dominant complaint on this family, and it is a dried-nozzle problem rather than an ink problem. Run a nozzle check, then a print head cleaning. If gaps remain, use Maintenance > Power Cleaning — but read Epson's two conditions first: every tank must be at least one-third full (running it low can damage the printer), and after one Power Cleaning you must power off and wait at least 12 hours before running another. It also consumes a lot of ink. Printing a color page every week or two prevents most of this; see whether ink dries out.
Ink levels wrong after refilling
The printer estimates levels by counting usage, not by measuring the tanks. Refill to the top line, select the colors you filled on the LCD and complete the reset — otherwise the gauge keeps reporting the old figure. Inspect the tanks visually rather than trusting the display.
ADF will not feed, or copies come out streaked or shifted
Check that the ADF icon lights on the Copy or Scan screen — if it does not, the printer has not detected the originals, so reload them. Do not load above the arrow mark on the edge guide, flatten curled or creased pages, and clean the inside of the ADF and the scanner glass. For shifted margins, also align the original to the corner symbol on the glass and set the correct Original Size in copy settings.
Maintenance box message
The ET-3843 routes waste ink from head cleaning into a replaceable maintenance box, part number T04D100. When it fills the printer stops. This is a genuine consumable and it is user-replaceable on this model, which is a real advantage over the cheaper ET-2800 and ET-4800 class, where the waste pads are not owner-serviceable.
Will not join Wi-Fi, or setup stalls
This printer is 2.4 GHz only. If your router broadcasts one merged network name across both bands, Epson's own guidance is to enable dual-band mode with separate SSIDs per band so the printer can see a 2.4 GHz network to join. Epson also currently carries an advisory that its Windows 11 installer can stall on this model; where the full driver will not install, Windows 11's built-in driver picks the printer up automatically once it is on the same network or attached by USB. Our printer Wi-Fi setup guide covers the Epson path in detail.
What EcoTank ET-3843 owners ask
These are the questions that come up most for this printer on retailer Q&A pages, Epson's support pages and owner reviews, answered in our words.
Why does the ink that came in the box print fewer pages than a new bottle?
The box has 127 mL of black and 70 mL of each color, but some of it is used to charge the ink system the first time. Replacement bottles are rated for about 7,500 black and 6,000 color pages.
How long will the starter ink last?
Epson says up to 2 years if you print about 200 pages a month.
What is the largest paper it takes?
Legal (8.5 x 14 in). The cassette holds up to 250 sheets of letter, legal or A4 plain paper.
Can several people print to it without going through the router?
Yes. Wi-Fi Direct lets up to 8 devices connect to the printer directly.
Can I put the cheap bottles labeled "502 / 512 / 522" in it?
Not if they are sublimation ink. Those bottles fit the ports, but sublimation is a heat-transfer ink and does not belong in a document printer. Look for plain Epson 502 or a 502-compatible ink.
EcoTank ET-3843 quirks worth knowing
- It uses a pigment black, which gives sharper text on plain paper, alongside dye-based colors, with Epson's PrecisionCore Heat-Free printhead.
- Its replacement, the ET-3943, takes the same 502 bottles, and Epson says its duty cycle is "twice as robust" as the ET-3843's.
- The bottles carry no chips. The printer estimates levels by counting, so you reset each tank on the LCD after you fill it.
FAQ
What ink does the Epson EcoTank ET-3843 use?
Epson 502 ink bottles in black, cyan, magenta and yellow. Nothing else fits.
Does the Epson EcoTank ET-3843 use Epson 522?
No. Epson's 522 compatibility list does not include the ET-3843, ET-3830 or ET-3850. It covers the ET-2800, ET-4800, ET-2903 and similar. The two families are not interchangeable.
Is there an Epson 502XL?
No. There is one bottle size. Epson markets 502 itself as ultra-high capacity, which is branding on the base product rather than a separate tier.
Which other printers use Epson 502?
The nearest cross-fits are the ET-3830, ET-3850, ET-3760, ET-4850, ET-4950, ET-2850, ET-2980, ET-15000 and the current ET-3943.
Can I use compatible 502 ink without voiding the warranty?
Yes. US law prevents a manufacturer voiding your warranty purely for using third-party supplies. See the legal answer.
Does the ET-3843 have a fax?
No. It prints, scans and copies, with an ADF and automatic duplex. Fax in this generation is on the ET-4850 and ET-4800.
Is the ET-3843 still made?
No, Epson has discontinued it — but 502 ink is current and widely stocked, and the replacement ET-3943 uses the same bottles.
Other printers that use Epson 502 bottles
Epson EcoTank ET-2750 · Epson EcoTank ET-2760 · Epson EcoTank ET-4750 · Epson EcoTank ET-4760 · Epson EcoTank ET-2980 · Epson EcoTank ET-4950 · Epson EcoTank ET-3950 · Epson EcoTank ET-2850
More Epson ink guides: Epson WorkForce Pro WF-4830 · Epson WorkForce WF-2950 · Epson Expression Premium XP-7100 · find any printer
Replacing it? Our highest-rated alternatives
- Epson EcoTank ET-2980 — CastleScore 90
- Epson EcoTank ET-2850 — CastleScore 86
- Epson WorkForce Pro WF-3820 — CastleScore 80
Sources
Ratings and prices were checked on October 9, 2026 and will change over time.
Need replacement Epson ink cartridges? Shop Epson ink cartridges at Castle Ink. Compatible, up to 70% less than OEM, and shipped the same day when you order by 4 PM ET.