Third-party status
WorksBottle-fed: no cartridge chip to block
Yes. The ET-3850 is filled from Epson 502 bottles, so there is no cartridge chip for firmware to reject. The real risks are print quality and Epson's warranty warning, not a lockout.
What to do now
What to buy instead
- Genuine Epson 502 bottles. The safe default, and keyed to fit.
- Compatible 502 bottles. Cheaper. Pick a seller with a return policy.
- Account required
- No
- Cartridges
- Epson 502 (T502) ink bottles
- Blocking firmware
- None reported
- Last checked
Also applies to: Other EcoTank models that take 502 bottles, such as the ET-2850 and ET-4850 (check your bottle number).
Third-party and remanufactured cartridges
- Epson lists 502 ink bottles (black 502120, cyan 502220, magenta 502320, yellow 502420) for the ET-3850, plus maintenance box T04D100.[1]
- Epson says its cartridge printers are designed for Epson cartridges only, and that such restrictions can be avoided with cartridge-free EcoTank printers.[2]
- Epson's ET-3850 product page warns that non-genuine ink could cause damage not covered by the printer's limited warranty.[3]
- On r/printers in December 2025, an ET-3850 owner said they use third-party ink; a long-time EcoTank user said they have never bought Epson ink and their printers last 5 to 6 years.[4]
Epson account and subscriptions
- We found no Epson requirement for an account or subscription to print on the ET-3850.[3]
Firmware that blocked cartridges
- We found no source tying an ET-3850 firmware update to blocking third-party ink. Epson's update warning is aimed at cartridge printers.[2]
To see your version, print a printer status report or open the printer's web page. Compare it with the firmware list.
Workarounds that sources back up
- Use ink sold for 502 EcoTank printers from a reputable seller, and refill before a tank runs dry.[1][4] Ink quality varies between sellers, and mixed inks are hard to flush out once in the tanks.
What does not reliably work
- There is no chip to reset or swap. Problems people report with third-party EcoTank ink are color shifts, weaker blacks, smearing or clogs, which are ink-quality issues, not firmware.[4][5]
What to buy instead
- Genuine Epson 502 bottles. The safe default, and keyed to fit. Shop
- Compatible 502 bottles. Cheaper. Pick a seller with a return policy. Shop
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What we could not verify
- Long-term print-head wear with third-party bottle ink in the ET-3850.
- How Epson handles warranty claims when third-party ink was used but not shown to cause the fault.
- Whether any future ET-3850 firmware will check ink in any way (no report found as of Nov 6, 2026).
Know something we missed? Dated sources beat opinions. Corrections go on the page with a date.
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Sources
- Epson FAQ: ET-3850 ink bottle and maintenance box part numbers (published Aug 5, 2021)
- Epson: information about third-party ink (read Nov 6, 2026)
- Epson: EcoTank ET-3850 product page (read Nov 6, 2026)
- r/printers: upgrading from an ET-3850 while using third-party ink (published Dec 30, 2025)
- r/printers: third-party ink quality problems in an EcoTank (ET-8550) (published Oct 16, 2025)