Bubbles in the coolant tube / Won't purge bubbles

My glowforge is stuck as the bubble purging stage and doesn’t seem to be purging any bubbles at all, does anyone know what could be causing this? I’ll attach an example image.
This is really worrying for me as I use it for my business and cannot currently run any prints.
Please let me know if anyone has any ideas.
Thanks so much.

Hi Toby, I’m just another owner, support will be along to help.
How long have you had the machine? It looks like you have been using it for a while. So it has been working fine?
I’m guessing the pump is cavatating, sucking air. That suggests a low coolant level.

Im assuming it has been working normally which means the coolant had to go somewhere. Look for fluid in the machine or under it. The pump is on the left side.

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Thanks for replying, we’ve been using it for about 7 months. I can’t find any free fluid but it did leak a little when it was initially transported. Do you know if there’s a way to check the coolant level or replace it? Thanks again

Your welcome! So when you first started the laser the bubbles in the tube cleared completely, and there were no bubbles until recently?

The coolant sump is there on the left with the pump, and that would be where coolant is added. You should wait for support’s official advice on how to accomplish that.
Good Luck!

The bubbles were purging successfully until today yes. Thanks so much for your help, hopefully support comes through soon!

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As @PrintToLaser stated:

But, I have no idea what GF uses but generally the coolant is only distilled water. Some high power laser use a combination of Antifreeze and coolant.

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I would use a flashlight and mirror to check the left side around the pump for fluid.

I’m just speculating, but if there is no fluid leaking I think it is possible there is a pinhole in the coolant return line allowing air to be drawn into the system, and the machine continues to purge it.
Too bad your first post is with a problem, but welcome to the community anyway!


I’ve just found a little liquid behind the coolant reservoir, hopefully support will get back to me soon and we can get it all sorted. Thanks for being so lovely and helpful.

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Often support will contact you here, and finish with the issue through email. I and other members would really like to know the resolution, if you wouldn’t mind posting about it.
Thanks! :sunglasses:


Hello @tobyhouseross - We’ve just responded to your email ticket for this issue, so please keep an eye on your inbox for that information! Since we’ve already been in touch via email I’m going to go ahead and close this topic.