The xTool P3 is a liquid-cooled CO₂ laser, and occasionally it stops mid-job with a low water flow error: COOL_WATER_MACHINE.ELEMENT_ABNORMAL.WATER_FLOW_LOW. This is the machine protecting itself: without sufficient cooling, the laser tube would be damaged. Here are the causes and how to rule them out without unnecessary disassembly.
This guide adapts xTool’s support documentation on the low flow error in the P3 into Spanish.
What the warning means
The P3’s laser tube needs a constant flow of coolant to avoid overheating. A sensor monitors that flow and, if it drops below a safe level, stops the job. Common causes:
- Outdated firmware or software.
- Incorrect antifreeze mixture (too concentrated).
- Blocked water flow (bent or pinched tubing).
- Cooling system problem.
1. Firmware and software up to date
Update the machine’s firmware and xTool Studio to the latest version and restart. This is the official first step for almost all errors and rules out false positives.
2. Check the antifreeze mixture
This is the most overlooked cause. If the antifreeze concentration is too high, the liquid becomes thicker, circulates worse, and triggers the flow error. Check:
- That the antifreeze ratio matches xTool’s recommendation.
- That you didn’t add too much when refilling the reservoir.
If you suspect the mixture is wrong, the correct action is to empty the reservoir and refill it with the correct concentration. Too dense a coolant not only causes this error but also cools less effectively.
3. Verify that water is circulating
With the machine on, the water pump should be running continuously. To check:
- Turn off the machine.
- Remove the top cover and the laser tube cover (follow the official video tutorial to avoid forcing anything).
- Turn it back on.
- Gently pinch the water tube and check if the liquid is flowing.
- If the flow seems normal, proceed to step 4.
- If it’s weak or intermittent, the problem is in the circuit: go to step 4.
4. Inspect the tubing
- Turn off the machine.
- Remove the back panel (per the video tutorial).
- Check if any tube is bent, pinched, or blocked.
If you find a bent tube, reposition it. A fold after moving the machine or maintenance is a surprisingly common cause.
5. The cooling system
If after all the above the error persists, the cooling system may need replacement. At this point, it’s best to rely on the official replacement video and, if you’re unsure, open a support ticket with xTool including a video of the problem.
Frequently Asked Questions
Can I use tap water instead of antifreeze?
No. xTool antifreeze is not just for cold weather: it contains additives that prevent corrosion and algae growth in the circuit. Tap water clogs the system over time. Use the recommended coolant in the proper ratio.
It happens in winter, in a cold workshop. Is that related?
It can be. In very cold conditions, an overly concentrated mixture thickens even more. Check the ratio; that’s the first thing to look at.
Is it dangerous to continue if I ignore the warning?
Yes. The warning protects the laser tube, which is an expensive part. Don’t force it: fix the flow issue before continuing.
Written by Noemi and Javi, from Picasita. We have been using a xTool P3 in production since October 2025; we are xTool affiliates. This guide adapts the brand’s official documentation; the original is available at their support center. More tutorials and solutions.
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