Epson EcoTank Tube Size, Ink Line Suction, and Missing Colors: Why Only One Color Prints After Cleaning

Question

I watched your video about reinstalling the Epson EcoTank tube guide and avoiding common mistakes. I'm trying to find out the correct hose or tube sizing for my printer. Right now, five of my six colors are not printing, and red is the only color that prints.

I have already flushed the printhead with cleaning solution, cleaned the dampers, siphoned ink from the ink tanks, and removed and cleaned the tanks. Could this be a suction issue, an ink tube issue, or something else in the ink delivery system? Any help would be appreciated.

Answer

Based on your description, there are two separate issues to think about: the correct ink tube size and the reason why only one of six colors is printing.

Since you mentioned six colors, I assume you are working with a six-color Epson EcoTank or a wider-format/photo-style model, such as an ET-8550-type printer or a similar six-channel ink system. For that kind of printer, tube size and tube length both matter. The tubing cannot simply be replaced with any random silicone or PVC hose that looks close enough. The internal diameter, outside diameter, stiffness, length, routing, and clamp position all affect ink movement.

For a six-color printer like the ET-8550, you would usually be looking for a six-strand tube assembly rather than individual generic tubing. We carry a replacement tubing set for that style of printer here: Replacement Tubing Set for ET-8550 6-Strand Tubes with 2 Tube Clamps [https://bchtechnologies.com/products/replacement-tubing-set-for-et-8550-6-strand-tubes-with-2-tube-clamps?_pos=10&_sid=3e658594a&_ss=r].

For many four-color desktop EcoTank models, Epson has used more than one tubing design. Some printers use four tubes that are all the same size. Other printers use a larger black ink tube and smaller color tubes. The type we currently have is the version where the black tube is larger than the other tubes: Used Genuine Ink Supply Tubing for EcoTank and Supertank Printers [https://bchtechnologies.com/products/used-genuine-ink-supply-tubing-for-ecotank-and-supertank-printers-et-2750-et-3750-et-4750-and-more-no-return?_pos=14&_sid=25220d18d&_ss=r].

However, the fact that only red is printing and the other five colors are not printing suggests the issue may not be just tube diameter. If five channels are missing at the same time, I would look at the whole ink delivery path and the cleaning station before assuming all five ink lines are bad.

One possibility is air in the ink lines. If the printer has been flushed, tanks removed, dampers cleaned, and ink siphoned out, air can easily enter the system. Once air gets into the ink tubes, dampers, or printhead inlet ports, the printer may not be able to recover with normal cleaning cycles. EcoTank printers rely on a balance between gravity feed, cap-top suction, damper control, and the printhead's internal channels. If too much air is introduced, the pump may pull air instead of ink.

Another possibility is a cap-top or pump suction problem. During a cleaning cycle, the printhead parks over the capping station, and the pump pulls ink through the nozzles. If the cap is not sealing against the printhead, the pump tube is disconnected, the waste ink line is clogged, or the pump is weak, the printer may not be able to draw ink through the missing colors. In that case, the issue may look like a printhead clog even though the real problem is poor suction at the maintenance station.

You can often test this by checking whether ink is being pulled into the waste line during a cleaning cycle. If the pump runs but no ink moves, then the cap-top may not be sealing, the pump may not be pulling, or the waste line may be blocked. If ink moves from only one channel or one color seems active while the others remain empty, then the issue could be isolated to the dampers, lines, manifold, or printhead channels.

The dampers are also important. Even if you cleaned them, they can still have internal restriction, damaged membranes, dried ink residue, or air pockets. A damper can look clean from the outside but still fail to pass ink properly. Also, if dampers were removed and reinstalled, they must seat tightly on the printhead nipples. A poor seal at the damper-to-printhead connection can allow air to enter instead of allowing ink to flow.

The tank side should also be checked. Since you siphoned ink from the tanks and removed and cleaned them, make sure the tank vents are open and the outlet ports are not blocked. If the vent is closed or obstructed, ink may not flow correctly because the tank cannot equalize pressure. On EcoTank systems, ink flow can stop if the tank cannot breathe. This can mimic a clog or suction problem.

Tube routing is another common mistake after reinstalling an EcoTank tube guide. The tubes must not be twisted, pinched, stretched, folded, or routed in a way that restricts carriage movement. If the tube guide is installed incorrectly, the tubes may kink when the carriage moves. Even a small kink can prevent ink flow. The tube length also matters because tubing that is too short can pull on the carriage, while tubing that is too long can sag, rub, pinch, or interfere with movement.

If the printer was printing before the cleaning work and then stopped printing five colors afterward, I would suspect air introduction, poor damper seating, tube misrouting, or loss of suction before assuming the printhead suddenly failed. On the other hand, if the printer sat unused for a long time or had severe dried ink before cleaning, the printhead may still have internal clogs even after flushing. Printhead flushing can help, but it can also push debris deeper into the head or damage the internal membrane if excessive pressure is used.

A good troubleshooting order would be:

First, confirm the exact printer model so you know whether you need a six-color tube assembly or a different EcoTank tubing configuration.

Second, inspect the ink lines for air gaps, kinks, flattened sections, or incorrect tube guide routing.

Third, confirm that each tank has ink, the outlets are open, and the vents are functioning.

Fourth, check that each damper is filled with ink and properly seated.

Fifth, verify that the capping station seals against the printhead and that the pump can pull ink into the waste line.

Sixth, avoid running too many cleaning cycles back-to-back. Excessive cleaning can fill the waste pad, overheat components, or worsen air movement in the lines.

If five colors are missing and only red prints, the problem is likely upstream of the nozzles or related to suction/priming unless those five printhead channels are completely blocked. The key is to determine whether ink is reaching the printhead. If ink is not reaching the printhead, focus on tanks, tubes, dampers, air leaks, and suction. If ink is reaching the printhead but still not printing, then the printhead channels, nozzle plate, or internal head structure may be clogged or damaged.

Addressing printer issues can be a complicated affair because many of these problems require hands-on inspection. For that reason, we are not able to provide remote troubleshooting, repair suggestions, or direct support for printer repairs. We do offer an in-person evaluation and repair service through our local diagnostic facility: BCH Technologies Printer Repair Service [https://bchtechnologies.com/printer-repair-service]. Because demand is high, we operate on a first-come, first-served basis, so it may take a few weeks before you can drop off your printer. Our repair services are structured to handle either a complete printer or specific parts, with clear instructions on how to proceed. However, we understand that our rates may not be the most economical option for everyone. Therefore, we strongly recommend using self-help resources and online research whenever possible. You can start with YouTube or visit our channel homepage at BCH Technologies on YouTube [https://youtube.com/@bchtechnologies]. Use the search icon next to "About" on the right-hand side of the menu bar to look for specific repair topics. I receive dozens of questions every day asking whether we have videos on certain subjects, and after creating videos for more than nine years, it is difficult to remember every single one. YouTube's search function is usually the fastest way to locate the most relevant video, and it may also recommend helpful videos from other channels.

Thank you again for reaching out and for watching our videos. I hope this helps you narrow the problem down between tube sizing, ink flow, air in the system, damper seating, and cleaning-station suction.