My glass oven door has just shattered and no-one was anywhere near it... why??

Question

I have a 3 or 4 year old double oven and we put the main oven on to pre-heat. Without warning the glass door just shattered and exploded onto the floor.

Any idea why?

I'm a bit worried in case the top one does the same.

My husband cleaned the door the day before, but he swears he only used diluted washing up liquid on it (but he did use oven cleaner on the insides).

Answer 1

I have seen this happen to the glass in cars and large panes of glass in buildings.
What causes it? Internal stress, Flaws in the manufacturing process, Poltergeists, your guess is as good as mine.
You need a new window for your oven, that's the bottom line.

Answer 2

Oven Door Glass Breaking Spontaneously

Answer 3

You were the victim of improper tempering.

In an effort to strengthen and condition a glass for hard use (impacts, temperature changes...) glass like the one in your oven door went through a strengthening process called tempering. Basically, after the glass was formed, the outside edge was heated and cooled very quickly. This made the outside of the glass cool faster than the inside. Because glass expands when heated and contracts when cooled, this uneven cooling puts an internal stress on the glass forming a compressive (strengthening) force on the surface. The problem with this process is it's inherantly unstable. It is very hard to uniformly heat and cool the outside of the glass when tempering so not only is there stress on the surface from the outer edge cooling faster but there are higher stress points where part of the surface cooled faster then its neighboring section. With use this stress becomes focused and can (as it did with your oven) cause the glass to violently shatter.

A sure sign of this type of failure is how the glass breaks. My guess is it didn't break the way your house windows would, but instead it "blew up" into many small pieces, some of them almost powderized. This is because to relieve all that internal stress the broken glass forms as much new surface area as possible, in this case a large number of small blunt pieces. This is called dicing.

You might find out who made the glass and go to them saying your glass was improperly tempered.

As a side note, most glass manufactures are moving away from tempering as a strengthening method for this very reason.

Answer 4

In most cases oven door glass isn't just ordinary glass, so don't contact the local glass company as some have suggested. Some oven doors contain up to three sheets of tempered safety glass installed in a specific order. The tempering process increases the strength of the glass to withstand high temperatures, which is especially necessary if you have a self-cleaning oven. Temperatures during self-cleaning can reach 1,000 degrees or higher. I'd suggest contacting a local appliance store or local branch of the manufacturer. Have your brand, appliance type, and model number ready.

Answer 5

The glass shattered due to a flaw in manufacturing, the glass is heat treated and a small imperfection during treatment has caused it to shatter, the chance of the top oven doing the same is unlikely.

Answer 6

I dont know the answer regarding your oven door but I had a new patio door once & after about a month that did the same thing & the supplier changed it without question & said that it happened quite a lot...... so I think your husband is off the hook (for now anyway ! )...... but I'm sure you'll be able to blame him for something else soon lol my missis usually does !

Answer 7

It sounds like he used too much liquid and it soaked into the sealing material. Once heated, the wet material expanded and blew out the glass. I wouldn't use the other oven for several days to give the moisture time to evaporate.

Answer 8

Not sure but the same thing happened to my ceramic hob - while I was out of the house!

Answer 9

Hi,it might have been with age.Your husband will not have caused it.