Overheating in a cool room

Continuing the discussion from Overheat shutoff in cool room:

I just experienced this issue. However, on mine, it never started back up. The web interface told me to wait a few minutes while the unit cools, but it just stayed that way. I was in the middle of a project so I let it “cool” for about 2 hours. Finally, I just turned if off and back on.

Project: currently I’m “engraving” a 10 1/8" circle with a fairly simple heart design. I’ve done two, and there’s been roughly 5 minutes between jobs (15 minute job). I was working through the third one when it happened.

I’m nervous to start this again because I’m just wasting materials. Any suggestions on how to keep this from happening?

I’m kind of curious. Have never received a cooling message so am clueless as to the cool down process.

On a Basic, if the overheat occurs at idle I can’t see how it would ever cool down unless the ambient temperature is reduced and the lid is open. The intake fan is not strong enough to balance the electronics load.

If it overheats during an engrave it’s because of the tube heating so it makes sense that it might cool down when at idle.

I can’t tell if there’s a question here or if you’re just chiming in.

The missing details you’ve eluded to: It’s a GF Pro. During the engraving process is when I encountered the problem, at which point the hardware set itself in a standing idle (did not home x/y axis). Ambient temp is ~72f (but close enough to a partially cracked window that I can run an exhaust tube out).

Let me know if that helps.

It was more of a, “this is the way I think it works”, and thinking somebody might tell me different.

I have a Pro also and cooling is something that could happen at higher ambient temps. But the Basic, once it overheats, might never come back unless the room is well below the threshold.


Would think at 72F it shouldn’t have any problem. Though I have seen the inside of my Pro a full 10F higher than ambient at idle.

Do you just use a non contact IR thermometer?

Just a standard wifi temp sensor inside the GF and the same sensor moved outside the GF near the air intake. Sensor may or may not be accurate overall but the difference should be fairly close.

Use an IR sensor too but have less confidence in its measurement of surface temps vs air temps.

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Thanks for reaching out. I’m sorry you weren’t able to complete your print.

Your Glowforge Pro features a closed-loop liquid cooling system that uses the air from the room to remove heat. It’s boosted by a solid-state thermoelectric cooler that allows for heavier use at higher ambient temperatures than the Basic. It is designed to print in an operating environment between 60 degrees Fahrenheit (16 Celsius) and 81 degrees Fahrenheit (27 Celsius). Printing outside these ranges may cause your unit to pause before starting, or to pause periodically during the print for cooling. This isn’t harmful, but it can make your print take a little longer.

You can try any of these things to improve warm-weather performance:

  • Try printing with no material on the bed (so as not to generate smoke and fumes) and no exhaust hose attached. If this works, then the problem may be that your exhaust hose is constricting the flow of air out of the unit, preventing cooling.
  • Examine the bottom-right side of your Glowforge. There are air intake vents, and if they become obstructed, it could make cooling less effective.
  • Try pointing a fan at the right side of your Glowforge. If there is warm air around the intake, this could help it cool off.
  • Power off your Glowforge and allow it to cool, then power it on and print immediately. When it sits idle, the fans are off, so heat can build up.
  • Just wait. Your print may take a little longer when it’s warm, but your Glowforge will protect itself and make sure it cools enough to prevent any loss of power or damage. And it’s clever enough to pick up from exactly where it left off, even if it loses Wi-Fi during the print!
  • If you are venting outdoors, ensure that changing conditions do not cause extreme temperatures or humidity to enter the Glowforge unit through the exhaust hose. Disconnect the hose from the outside air when the Glowforge is not in use.

If you are using your Glowforge in a room that meets operating environment guidelines and you are still running into trouble, please let us know the following so that we can make sure everything is ship shape:

  1. A description of the steps you took, what happened and what you expected
  2. The temperature of the room where you are currently using your Glowforge
  3. The date and time (including time zone) when you saw the cooling message
  4. Photos of your exhaust setup

Let me know how it goes!

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Your description of the problem sounds like me for the first week I had my unit (late May). I received those steps from support and took action by installing an inline duct fan at the window-end of the exhaust hose. That fan now stays on 24/7 and I’ve hardly had any cooling occurrences at all since that change (and none more than ~2 mins). It also helps the smell drastically by literally sucking all residual odor from the unit at all times.

The duct fan is one that I had laying around from a previous project and is a 190 CFM 4” Inline Duct Fan on an adjustable controller. The cost of the whole outfit was approx. $125 from Amazon.


It’s been a little while since I’ve seen any replies on this thread so I’m going to close it. If you still need help with this please either start a new thread or email support@glowforge.com.

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