Why are houses not going up in flames over ovens and irons being left on?

Question

I'm aware of someone accidentally leaving the burner on, twice (once with something on the range, once without). Clothes irons are left on as well. Things like this must be happening relatively frequently, yet I don't hear about buildings burning down very often. Why?

Answer 1

A clothes iron left on, in the normal upright position they sit when not actually actively ironing has nothing in contact with the heated surface to set on fire. It just wastes electricity and heats the air a bit.

Unless at the highest settings, the heated surface is too cool to ignite or scorch anything, anyway. You'd have to have it set high and leave it face down on cloth or paper for that to be a risk. In my circle of acquaintance actually using an iron at all is uncommon in the extreme for many decades now. I think I turned mine on last when opening an annoyingly glued to make it hard to service cell phone.

An oven can run basically forever without setting the house on fire, though the contents, if any, might set off the smoke alarm after a while. They are designed to contain the heat inside them and not become so hot anything would ignite outside them.

Stovetop burners likewise can run forever without issue - only if there's a large amount of oil is there any significant fire risk, rather than heating the general area and ruining a pan (and setting off smoke alarms if there's food in a pan on them, again.)

Some more "modern" stoves also have a "feature" that will turn off a burner after 3-4 hours, which is extremely annoying if you are simmering something slowly and wander back into the kitchen and find it showing turned on, but it's shut off. There are also external timer devices for folks with known forgetfulness issues that have to be turned on to use the stove and will shut it off after an hour or so unless reset.

Smoke alarms, which I've mentioned twice, are another factor in this. They alert people that there is a problem before it gets all the way out of hand, sometimes.

It all comes down to learning from mistakes that killed people and burnt down houses and regulating to prevent future deaths and houses burning. Cities with bad historical fires like London and Chicago have rather extreme measures for the latter part.

Answer 2

A few additional points to add to Ecnerwal's excellent answer:

• Ovens

Many modern ovens have an automatic 12-hour shutoff. This is actually a problem for Orthodox Jews on certain holidays. As a result, a number of manufacturers, such as KitchenAid, have consulted with Jewish religious authorities and created "Sabbath Mode" ovens. These do not turn off after 12 hours and are also designed so that no indicator lights or other direct electric actions happen when opening/closing the door. I don't actually know whether the 12-hour shutoff was designed as a safety measure or an energy saving measure.

Generally speaking ovens contain fires very well. If your casserole catches fire, turn off the oven but don't open the door until the fire is out.

• Irons

I remember many years ago seeing, in close succession, both an insurance ad using "oops, I left the iron" followed by "house burning down" and also an ad for a brand of iron that included automatic shutoff after a few minutes. I'm actually not sure why this isn't a standard feature. Then again, maybe it is. Last two times I used an iron were for countertop edges and for ironing kids' Perler Beads creations, both many years ago. (And in case anyone didn't know, you shouldn't let your kids play with Perler Beads near the basement floor drain - you'll regret it weeks/months later while snaking the main drain.)

• Cooktop

This is actually the most likely problem, in my opinion. An iron you usually use for a few minutes and turn it off. An oven can go a long time without a problem - and even a fire is not usually a problem (it might ruin the oven but it is very unlikely to damage the rest of the house). But it is quite common to leave things (e.g., soup) cooking on a burner for a few hours, so forgetting about it or leaving the house for a quick errand that turns into hours, etc., followed by the contents of the bottom drying out and starting a fire definitely happens. Aside from simply not forgetting things, keeping flammable items (cookbooks, raw ingredients, etc.) away from the cooktop minimizes the problem. But that problem does exist.