Too Chill: Chiller freezing

Hey all, long time no see!
I think my home laser’s chiller died.
It’s a “cool master 500”, and has an E5 error, which according to the front is the water temp sensor.
Which means the chiller actually freezes the water in the reservoir.

I don’t see that exact model on the market anymore. Does anyone have an opinion to share on a new chiller for a 100w laser? Anyone in the market to be paid to fix a sensor on this one?


A used CW5000 or CW5200 would be best if you can get it. Next best is to buy new but don’t be too tempted by the small savings from an off brand. Just recently I recommended this to Tom of Lumbercycle for their 100watt laser.

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Thanks. I have never been totally happy with the one I got. I guess the proceeds from this job will cover the new one!

Hi Susan and wow, I don’t see anything looking like a water chiller by the name of “Cool Master 500”. Without knowing what type of temp sensor it is using it’d have to be a “tear apart and see what’s up” type of attempted repair. Could be an electronic part which could probably be sourced or it could be an old-school sealed pressure tube type of sensor / controller which can be hard to find.

Can you post a picture of the manufacturer label which should have Make, Model Mfg year and other specs? Maybe there’s something there which turns up better search results.

On the plus side the CW-5000 is a common chiller and is generally well liked.

I’ll get to back tomorrow, but the front looks like this.

I’m thinking the CW-5000 is a better investment than trying to fix this one.

The control system of these are on/off mechanisms since a compressor doesn’t really run a different speeds. Without thermostatic control(ie knowing what the temp is) the compressor circuit probably doesn’t turn off and the error code is showing up because there’s a realistic time limit for how long it should ever run. Normally compressors fail and this unit does seem to still work.

From the text on the front panel this unit looks like it has a high percentage of Chinesium in it and probably wasn’t sold much in the States. The CW units seem to dominate searches for laser water chiller units.

If you do go the route of a CW-5000 I would be willing to take that unit off your hands. I need another project like I need a hole in the head but I also have a problem where my “cooling” system for my K40 is a stand-up office water bubbler/cooler which stands in front of my laser. Fitting it under the laser will take a few hours of cutting, moving and case rework. Even if it’ll take an Arduino, SSR and JK thermistor to get the Cool Master 500 functional it would be time worth spending. I’m used to having Franken-device_name_here around there and much to my wife’s and daughters comedic pleasure.

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Sadly many of us suffer from this malady.

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Hey! I found the way to fix this one, was order the other one.

@DougL … It seems to work now, but I do NOT trust it, and I HATE to change the bulb in my laser (ask Alan!). So I would be thrilled for you to take this e-waste off my hands. I am not interested in fixing it for myself.

I did go through with using it this morning… as I was desperate to get a job done. I emptied the water as it was freezing, replaced with warm water, and the error code changed to e3… And it started showing what temperature it thought it was reaching again… AND it seemed to stop freezing the water…

YMMV, I will let you know when my new chiller arrives and is in working position. Until then I have to rely on the Cool Master 500 … It definitely is flowing because I did the ‘squeeze the hose’ test and got a different error code.

Susan (who has been personally rebuilt enough times physically and emotionally to go by FrankenSusan for years now… I respect a good franken-project, but just not for this usage)

Cheers !!