The various companies who make crock-pot or slow cookers have gravitated toward clear glass lids, some with locks, some without. The lids are made specifically to stand up to the kind of heat exposure expected of slow cookers on setting from “warm” all the way up to “high”.
I had set up a dish the night before in a pot with a locking lid, without the locks engaged, turned it on, and headed for bed. After checking the dish again first thing in the morning, I lowered the heat and allowed it to continue to simmer. When I came back in an hour or so later, I found this.
The lid shattered into pieces that maintained their position and shape until I experimentally tried to lift the lid by the handle.The handle popped up with bits of glass clinging to it.
I was utterly flabbergasted. I understand that glass is a non-porous amorphous solid, that it will “run” over time, that it is an extremely useful material in our daily lives, and that any single piece of glass will have a stress-point that can cause it to shatter like my crock lid.
I’m not inclined to think the slow cooker itself is defective. More that the glass of the lid found it’s weak point and gave in.
Other kitchen witches out there have encountered lids that shattered explosively, as well as a few who have had a similar experience to my own. A popping sound is often reported with this sort of incident, though I do not recall hearing anything when my lid cracked.
Fortunately, a replacement lid was available online for a relatively small price, and the crock-pot was back in use before too many days had passed with no repeat of our little adventure.
As with any appliance in the kitchen, please be sure to read the instructions and take good care of your equipment. Things like this will happen and it’s best to be prepared.
–Ann Cathey
thewanderingtexans 
Glad I found this. One sentence caught my eye when you said “I had set up a dish the night before in a pot with a locking lid, without the locks engaged,”. I had my crockpot with locking lid for a few years and always locked it down. The lid never fit that tight and it did have a vent hole to release the pressure. I can easily slide the lid around despite the latches being locked. Never had any problems despite me using this crockpot with the lid locked. So does it really matter if the thing is locked or not? I’m more likely to believe fastening handles and latches on the glass can weaken the glass with maybe a little help from heat whether the lid is locked or not. I notice that glass lids without latches even shatter. What do you think?
Personally, I think it’s all about the glass itself. Every piece of glass in the world has a weak point. When that point decides to crack, it’s going to crack whether it’s set off by the ambient heat of cooking, spattering grease or other fluids, being bumped, or any other possibility that might affect the piece of glass. For slow cooker lids, it may be the type of glass (there have been a lot of incidents being reported with Pioneer Woman brand slow cookers, recently), or the amount of use a cooker sees, or just the infamous weak point in the glass giving up. Locking the lid or not locking the lid isn’t as big a factor, in my opinion.
I had my crockpot lid shatter this morning. It was a Christmas present and yesterday was the first time I used it. Worked great all day, had a great dinner, washed the pot and dishes.
Went to bed several hours later. My husband got up made coffee and left for work and everything was normal. I got up an hour later and found the glass lid had exploded.
What the heck? Glass everywhere. This is like 12 hours after being exposed to any heat or cold. No one was anywhere near it??????
There was a flaw in the glass, more than likely. It’s not something that leaves any kind of mark. The “Pioneer Woman” brand of slow cooker was having some issues with shattered lids – lots of them. If your slow cooker was CrockPot or another major brand, contact the manufacturer. It may be under warranty and they will send you a replacement. If not, a replacement lid can generally be found online for about $10-12. I’ve only ever had one lid shatter in my 20-odd years of cooking with them.
I was very upset set. Last night I was putting things in the crock pot and the lid exploded. Glass all over even in the wall. I got ot for Christmas and only used it twice.
Contact the company that madethe cooker, and send them photos if you took any. they need to know that the product was defective. If they are really good, they will send you a replacement lid.
Don’t let this turn you against slow cooking! Parts breaking due to normal use are not terribly common, though they do occur, just like any other small appliance. I’ve got six slow cookers, with five in regular use and they are pretty darned dependable and have beenf or years. 🙂