Why Are the Blue and Yellow Channels Not Flowing on the Water Tornado Printhead?

Customer Question:
I recently removed the printhead on my Water Tornado printer to rework the stripped screw holes using your repair kit. While taking the opportunity to flush the printhead, I noticed that the Blue and Yellow lines—located on the outermost sides of the printhead—aren’t flowing at all. I had no printing issues with these channels before. The other lines were slow to flow, but these two are completely at a standstill. What could be the cause?

Answer:
Understanding the Problem with the Blue and Yellow Lines

When the Blue (Cyan or Light Cyan) and Yellow channels on the far sides of the printhead don’t flow—despite working well before—the issue is often related to internal clogging or ink chamber resistance rather than external obstructions. Since you were proactively flushing the head during disassembly, this is an ideal opportunity to address it.

Common Causes and Fixes

1. Backflow Resistance from Built-Up Ink or Air Pockets
   If these lines aren’t flowing even with mild suction applied, the culprit might be:

   • Dried ink residue or sediment built up inside the ink chamber

   • Airlock formation within the internal microchannels

   • Partially collapsed diaphragm inside the ink chamber, especially if the printhead was left dry for a period

   Fix:
   You’re already on the right path. Start by gently sucking on the ink lines to help draw the ink through. Sometimes, this jump-starts the ink flow and breaks minor airlocks. If that doesn’t help, try:

   • Soaking the nozzles with a cleaning solution like BCH’s printhead cleaner for pigment or dye ink

   • Using a flush syringe with a low-pressure adapter to gently push cleaning fluid through the channels

   • Repeating this a few times with intervals, allowing the solution to sit inside the chamber for 15–20 minutes to dissolve any buildup

2. Printhead Position and Gravity Effects
   If the printhead is removed from the printer and disconnected from the capping station, it loses the siphon pressure that typically helps maintain ink flow. That can make flushing more difficult, especially in the outer channels where resistance may be higher.

3. Contamination or Partial Blockage of the Damper Inlets
   If you have dampers connected, ensure they’re not clogged. Try switching tubes from a working channel to the Blue or Yellow one to see if the blockage moves or remains, which helps isolate the issue.

4. Mechanical Damage During Removal
   Rarely, the nozzle plate or inlet ports may become slightly pinched during disassembly, which could restrict the flow to those two channels. Inspect closely for cracks or warping around the plastic ports.

Other Considerations

• If the inner channels flow (even slowly) but the outer channels don’t, it’s likely an internal imbalance rather than a general clog.

• Be cautious using too much pressure when flushing. Excessive force could damage the fine nozzle screens or burst internal seals.

Printer repair is hands-on work and can be quite challenging. That’s why we can’t offer remote troubleshooting or personalized support for technical repairs. However, we do provide in-person diagnostic services through our local facility. You can learn more on our Printer Repair Service page (https://bchtechnologies.com/printer-repair-service). Please note that appointments operate on a first-come, first-served basis, and there may be a waiting period of several weeks. We provide both full-unit repairs and part-level service with step-by-step guidance. That said, we understand our pricing might not suit every budget, so we encourage DIY solutions whenever possible.

To help yourself further, visit our YouTube channel homepage (https://youtube.com/@bchtechnologies). Use the search icon next to the “About” tab to locate specific videos. We've created hundreds of videos over the last nine years, so using search will be faster than asking about individual topics. YouTube might also suggest related videos that can guide you, even from other creators.

Thank you again for your question and for trusting us to help. We're always here to support your printer journey!