What you should not cook in a toaster oven are liquids such as soup, rice, greasy or fatty foods or delicate pastries or seeds and nuts that are left unattended.
Seeds and nuts can quickly burn in a toaster oven due to the high heat and close proximity of the heating elements.
Delicate pastries and sugar glazes can burn and melt from the high heat and uneven heat of the toaster oven and also ruin the texture of the delicate pastries.
Liquids and soups will take longer in a toaster oven and could also spill out.
And toaster ovens cannot boil water and rice requires boiling water to cook properly.
And fatty or greasy foods, while can be cooked in a toaster oven can result in the fat or grease dripping onto the heating elements of the toaster oven and cause smoke and possible fires.
The disadvantage of a toaster oven is that the toaster oven is often slower at cooking foods than traditional ovens.
Other disadvantages of a toaster oven are the limited capacity of the toaster oven, the toaster oven could cook food unevenly as a result of the close proximity of the heating elements to the food and toaster ovens can take longer to cook foods than a microwave and can also be difficult to clean.
The smaller size of a toaster oven can make it difficult to cook large amounts or food or multiple foods at once.
Toaster ovens are great at cooking small amounts of food and use less electricity than traditional electric ovens.
But for more than one person a traditional oven can be much better.
A toaster oven should last a minimum of 3 years to 5 years.
However some toaster ovens may last longer than 3 to 5 years and some toaster ovens may rust out before they actually go bad and quit working.
The lifespan of a toaster oven also includes things such as how often the toaster oven is used, how well care for the toaster oven is and also the quality of the toaster oven.
Regular cleaning of the toaster oven and avoiding damage to the heating elements can help extend the lifespan of the toaster oven.
I have a Kitchen Electrics toaster oven that was given to me by neighbor that was moving and it was 5 years old when he gave it to me 5 years ago.
It's still working 5 years later and the toaster oven is now 10 years old and although the toaster oven does have a bit of rust in the bottom of the toaster oven, the toaster oven still works perfectly.
But I've also had a toaster oven last only 3 years and so it can vary.
The most common failure for toaster ovens is degradation of the heating elements over time and problems with the timer and switches.
Regularly cleaning of your toaster oven to remove any food particles and crumbs and keeping the toaster oven dry can help extend the life of the toaster oven.
Frequent use of the toaster oven, especially when cooking moisture heavy foods can shorten the lifespan of the toaster oven.
And poor wiring and power surges can also damage the toaster oven.
Higher end more expensive toaster ovens tend to last a bit longer than cheaper toaster ovens, although even a more expensive toaster oven can fail prematurely.
Signs that it's time to replace your toaster oven include it's completely stopped working, the cord is damaged, the toaster oven no longer is heating effectively as it used to, the knobs or timers are not working or the glass is cracked.