Amber Button - Too hot then too cold

I have a glowforge plus.
For the past few days I have been getting a “cooling down” error. I cleaned my air assist fan, my inline fan and my entire Glowforge. It did a 30 minute engrave without acting up and now It’s now alternating between cooling down & too cold. I tried calling for support but it just hangs up before I can leave a message.
The room temperature is 21 Celsius. It only seems to be happening on engraving and not cutting.

Please help!

Are you venting outside? It’s possible cold air is coming in through your vent so even if the room is warm enough the laser itself is too cold…

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It isn’t too cold. The exhaust fan is on so I don’t think any cold air would be getting inside.

Well the next thing to check would be the cable ends, check each one for debris, or teeth out of place, or cracks. That’s much more complicated so starting with wind is always easier!

Yes so far i have cleaned all fans taken the air assist fan assembly out and cleaned the fan really good with Reccomended electronic degreaser.

The machine is locking up mid print saying it’s to hot we reboot the machine and 20 seconds later it’s saying it’s too cold to start the machine. If I had to guess the temp sensor itself is acting up.

Guess I will wait for support to read the thread.


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So completely removed air assist fan and cleaned anything out of it and tested again still locking up on cooling down. This is really unfortunate during busiest moth of the year please help…


If there is a strong wind on one side of the house, it could indeed build up enough pressure on the windward side to back up against the fan and it would only take a whiff of a bit of below-freezing air to set off the cold sensor. It would not surprise me if there were separate sensors so it could be too hot and too cold at the same time :upside_down_face:

If there are louvers or similar to make sure that the air goes only one way, this would be less likely a problem. Alternatively, the sensors are connected through the white cable, and any cracked cables or almost connected pins could mess that up.

We just went and brought a one way dryer vent to prevent air from getting back in and it’s still not working. :frowning:

Going through this list and posting pictures would be a next step…


Your Glowforge features a closed-loop liquid cooling system that uses the air from the room to remove heat. It is designed to be used when the temperature next to your Glowforge is between 60 degrees Fahrenheit (16 Celsius) and 75 degrees Fahrenheit (24 Celsius). To check, put a room thermometer next to the right hand side of the Glowforge; it draws in air from underneath, on the right.

I extracted logs from your Glowforge and it looks like it is too cold which is causing the issue can I ask if the vent tube is always venting outside or is it placed outside only during prints?

Another option is to use a small heater in the room with the Glowforge to keep it warmer.

If you are still running into trouble, please let us know the following so that we can investigate further:

  1. A description of the things you tried and what happened

  2. If possible, place a thermometer next to your Glowforge on the right hand side and measure the temperature there; if not, estimate the room temperature

  3. The date and time (including time zone) when you had the problem

  4. Take a picture of the exhaust hose behind your Glowforge that includes the part where it connects to your Glowforge, and the part where it exits the room

Hi David

I replied to another staff member in an email (Request 366497)

As i said to her i discovered one of the wires on the Interconnect Board - Pump flow sensor was disconnected the gauge wire used for these connectors is super thin a 20 gauge or higher something you may want to look at upgrading in future builds where this cable is routed under stuff and put at an awkward angle when the machine is built.

In order to get running again i had to Sauder the wire back too the connector head. I will defiantly require a new wire.

I think it could be a sensor problem how does the machine go from being too hot and stopping printing to being rebooted and less than 30 seconds later being too cold to start that makes no sense.

But i do vent outside and use an inline booster and a one way flap that stay on when venting outside so not sure how any cold air would come back down the line when its being forced out the window.


I see you already emailed us about this and we’re working on it there, so I’m going to close this topic.