I’m getting really tired wasting time and brain-power on this, but unlike buying regular consumer goods (like the items on Amazon with hundreds to thousands of reviews) buying and dealing with research equipment is subject to really small sample sizes, so the more information that’s out there the better. Thus, I’ll keep this page as a running log of my experience with Stirling’s XLE Ultra Low Temperature (aka. -80*C) freezer.

TL;DR -> My 1 year-old freezer failed in the most catastrophic way: the firmware froze and displayed -80*C while the contents slowly thawed as it had reached 5*C by the time I noticed it wasn’t working. No alarms, as the firmware had crashed and was frozen (again, displaying -80*C the whole time). While I’ve had no issue with their mechanics, I suspect their firmware is potentially critically flawed.

Part 1) Discovering that the freezer had failed: I purchased a Stirling Ultracold SU780XLE, a little over a year now (purchased ~ October 2019), shortly after I started up my lab at CWRU. I’ve been in labs that had poor experiences with the ThermoFisher TSU series freezers, and the reviews for the Stirling seemed pretty good on twitter. Furthermore, CWRU has a rebate program with Stirling due to their energy efficiency, and probably also because they are local (they are based in Ohio).

I went into the lab last Sunday evening (Nov 8) to do some work. I went to retrieve something from my the Stirling -80*C, and saw that the usual ice on the front of the inner doors were gone. I opened up the inner doors and looked at the shelves, and there was water pooled on every shelf. I looked at some of the most recent preserved cryovials of cells we had temporarily stored on one of the shelves, and they were all liquid. Things had clearly thawed inside the freezer. I closed the outer door and looked at the screen at the top, and it was displaying -80*C. The screen is actually a touchscreen, so I tried to flip through its settings, but it was completely unresponsive to my touch. It became pretty clear to me in that moment that the freezer firmware had crashed with the screen displaying -80*C. Ooof.

I pulled the freezer out from the wall, found the on/off switch, and switched it to OFF. The first time, I actually flipped the switch too soon to ON, as the screen never reset. I’m guessing there must be some short term battery / capacitor that allows the freezer to keep running with momentary interruptions in power. So I then set it to OFF, waited for the screen to go blank, and then set it back to on. After booting up, the screen displayed 5*C. So there we go. It was indeed stuck on that screen, and rebooting the firmware showed it to show the real temperature again. Which is a VERY BAD real temperature.

I immediately emailed Stirling (email timestamped Sun, Nov 8, 7:37 PM). I received a response from a customer service representative Mon, Nov 9, 8:01 AM saying “I’m sorry to hear that you are having issues.” and that they were referring me to the service dept. Got an email from the Stirling service department Mon Nov 9, 8:39 AM asking for more information and a picture of the device’s service screen. I replied to this email with all requested information Mon, Nov 9, 10:43 AM. I got an email telling me I was “Incident-7576” on Mon, Nov 9, 11:00 AM. Complete radio silence from them as of writing this section of this post, which is ~ 72 hours later (Thurs, Nov 12, ~ 11:00 AM), even after I sent them a pretty strongly worded email yesterday at 6:00 AM. I’ll follow up on my continued experience interacting with the company in section 3 of this post.

Otherwise, the mechanics for the freezer seemed to be fine. It look me about an hour to mop up all of the water, and look through my boxes to see what had thawed (which was everything except the 15ml conicals, which seemed to have enough mass to them to have not fully thawed). I was still very aggravated and in a bit of shock to have had to deal with this, but still went about my work. Two hours later, the freezer was back down to -30*C. The next morning, it was back at -80*C. So the reset was clearly sufficient to make the freezer operational* again. ( *since it presumably still encodes the same firmware glitch which caused the problem in the first place).

Part 2) Taking stock of my lost items and forming my interpretation of what happened: Over the next couple of days, I had a chance to take stock of everything I had lost during the thaw. Being a new lab (and thus with a ~ 1 year old freezer) we didn’t have a ton of items in there, but they were not inconsequential. The commercial reagents were largely competent bacterial cells, which amounted to ~ $2,110 of lost material. There were also ~ $720 worth of chemicals, which upon freeze thaw cycles, are of somewhat questionable potency, and will likely need to be purchased again before use in publication. There were also dozens of cryovials of cell lines made in house. There were also a few cryovials of cells, dozens of tubes of patient serum, and viral stocks for SARS-CoV-2 research either given by other labs or provided by BEI resources, which would need to be replaced as we have no backups. While there is no monetary value associated with these reagents, the amount of work-time used in creating them and now replacing them is a major loss.

As a scientist, I think it’s natural for me to try to synthesize all the information I have to piece together what happened. There was no power loss (it was a sunny weekend without any storms, and no other equipment in the lab had any aberrant behavior). Nobody had gone into it for any extended amount of time, especially since it was over the weekend. The last time I had gone into it was Friday afternoon, when it seemed fine. That said, it is very well possible it had already crashed at that time. I don’t think I can visually tell the difference between a freezer at -80*C, -40*C, or maybe even -10*C. Frozen looks frozen. In lieu of any alarms or temperature readings provided by the freezer itself, the only visual clue was going to be water from the thawed ice in the freezer, which by that point was going to be too late.

To see if I could figure out when the freezer may have crashed / failed, I tried going back into the freezer log. This is all the information I could glean from the freezer:

So, uh, that history feature wasn’t all that informative, but still a couple of points I could glean from looking at it.
1) It goes from -80*C in the data points directly preceding the event, to being > 0*C to when I restarted it. So it completely stopped logging during the event. This is entirely consistent with the software having crashed, and the reason it was still showing -80*C on the screen while it had thawed.
2) Uhhhh. I can’t actually figure out what day and time it failed b/c it had apparently logged its most recent operation as August 26th. Clearly it wasn’t August 26th when it had failed, since August 26th was 72 days before Fri, Nov 6, which was the last time I had looked in the freezer before the event, when it was clearly still completely frozen. Weirdly, I didn’t have to tell it what day it was after I reset it, so it must have had an internal clock that knew it was Nov 8th upon the reset. So here’s another indication of there being something glitchy with their firmware.

Ironically, I had a separate low-temperature thermometer plugged into it TraceableLIVE® ULT Thermometer, Item#: LABC3-6510, which really isn’t a bad thermometer, but it eats up batteries and I ran out of disposable AAA batteries (I don’t think it takes a wall plug, which it should also do so it only needs to use the batteries during power-outage situations!), so I was waiting for some rechargeable AAAs to come in from Amazon. TBH, they had already come in a week or two ago, but the freezer was operating perfectly fine until this so it wasn’t high up on my to-do list to charge and replace the batteries and get the secondary thermometer up and running again. In hindsight, a very naive and critical mistake!

Part 3) Stirling’s response to this:

Thurs, Nov 12, 11:00 AM: So far, it’s been pretty nonexistent. I wrote them an email yesterday (Nov 11) saying 1) Everything I’ve seen is telling me this is a catastrophic failure of the freezer itself, so are you going to take responsibility for it? 2) I’m still quite worried about the freezer’s operation, since the glitch that caused this has not been addressed. I’m yet to get any non-automated response from them past the most recent email on Nov 9, 11 AM.

Thurs, Nov 12, ~ 5:00 PM: Tweeting about my experience seemed to have escalated things, as I got two phone calls. The first was from the technician handling my case (“Incident-7576”), who asked if anyone had been in touch with me about scheduling the fix on the previous Monday and Tuesday. I said no, this is the first response I had gotten. I also pointed out hat I had emailed him yesterday with some questions. Apparently he had not seem the email. So, a rather poorly managed customer and technical service response.

As soon as I got off the phone, the VP of Global Services called me (this is where I think the tweets likely made a difference). Provided apologies (as expected), but I also got to ask for answers to my specific questions. Here are things I learned:
1) “We’re not responsible for sample loss”. So they won’t cover anything that you lose if the freeze fails and thaws, even if it was in the most spectacularly bad way completely due to flaws in freezer design or production that torpedoes its operation.
2) The mechanics are covered for 7 yrs, but the material and labor warranty is only for 2 yrs. This includes things like “door handles and electronics”, with electronics clearly being the most relevant item here. They offered to extend this warranty to 3 yrs. I don’t think I’m unreasonable to feel like that is a pretty weak gesture based on the freezer failing the way it did.
3) I’ve had people tell me I should ask for a refund to get it replaced. Well, they don’t do that.
4) Apparently there are three parts to their firmware. One of them is called the “Beagle Bone”, which they said is responsible for making the real-time connection between the freezer settings and the parts. Quick google search suggests it’s something like this.

The saga continues. Let’s see what the technicians tomorrow say.

Fri, Nov 13th: Causing a stir on twitter apparently kicked things into action. I also put my detective hat on and I think I figured out what was going on. Too much to bury way down here, so I made a new post.