A convection oven works mostly the same way that a conventional oven does, with the exception of the airflow throughout the cooking area. Fans blow inside a convection oven to circulate the heat evenly, making conditions favorable for baking and other cooking applications. But if your convection oven isn't working -- there could be several reasons why -- then it's not good for much of anything. Some common causes for failing or malfunctioning convection ovens include power supply issues, burnt out elements, faulty convection fans and improper settings.
An electric convection oven's power source is a logical place to check first if the oven is not working. If there appears to be no power to the unit, check if the oven is plugged in properly and the power cord is in good repair. If so, check the circuit breaker to make sure the assigned fuse hasn't tripped. As a last resort, check the outlet itself for electrical current, even by plugging another appliance into it. Be sure to consult a professional electrician if you suspect any major electrical or wiring issues.
Burned Out Elements
One of the most common problems with any type of oven, including convection ovens, is burned out heating elements. These components are the parts that get hot and actually produce the radiant heat needed to cook the food inside. They are usually black and about as thick as a pencil. They glow red when heated if they are working properly. A burned out element will not heat or turn red. They can easily be replaced. Elements have a limited life span, but they should last several years.
The convection fan is located inside the cooking compartment of the oven. It circulates air to help food cook evenly in the intense heat. If the fan goes out on your convection oven, then food may cook improperly, sometimes burning on one side and undercooking on another. The fan motor could be bad and it may need to be replaced. However, just because you don't hear the fan turn doesn't necessarily mean it's the problem. Most convection oven fans do not begin circulating immediately after turning on the oven. The fan does not turn on until the oven is heated to the desired temperature. Wait it out to be sure there is actually a problem.
User error is a more common problem with home appliances than you might think. Sometimes you aren't getting the proper response out of your convection oven because you don't have it turned on correctly. Check your settings and make sure it is set according to manufacturer recommendations for cooking. For example, be sure that the dials on your oven are set to "bake" or "broil" and that the appropriate temperature has been set for cooking. If the dial is set to "off" or another setting then the oven will not heat at all or may do some other task such as self-cleaning. The latter would make the oven get far too hot for cooking.