Electric combination range/ovens are stoves that have both surface burners and an oven. Depending on their features, some electric range/oven units are quite complex. To understand how they work, let's look at the following areas:
There are many variations of range/oven combination units. We'll describe the following controls and devices, their function, and the interaction they may have with other components.
The thermostat is right behind the knob you use to set the oven baking temperature. There's a long, thin copper tube attached to this knob that leads into the oven compartment. It senses the temperature inside the oven and signals the thermostat to provide or prevent further heating.
There's another type of thermostat--an electronic/mechanical hybrid unit--that has a small electronic circuit board behind the knob. It has a sensor attached to it--about the size of a 4- to 6-inch pencil, that protrudes into the oven. When the oven reaches the temperature you set, the sensor signals the circuit board, which turns off the electric burner(s) in the oven.
The clock is either electronic or mechanical:
Electronic clocks have a lighted, digital readout. These are not usually repairable; when they fail, you usually need to replace the whole clock.
Mechanical clocks usually have three dials--the clock dial, a Start time dial, and a Stop time dial. You set the main clock to the time of day. Then, when you choose a time-bake or self-clean cycle, the clock turns on the oven at the start time and turns it off at the stop time. The Start and Stop dials are for both timed baking and self-cleaning.
Some range/ovens have a keypad for setting all of the oven, broiler, timed bake, and self-cleaning times, and temperatures. These keypads can't be serviced; you usually need to replace them when a problem arises.
Selector switch for bake/broil/timed bake, etc.
Electric range/ovens have at least one control switch for the oven/broiler. On some units, this is the same switch as the thermostat, on others it is a separate switch.
If it's a separate switch, it works in conjunction with the thermostat. You set the thermostat to the cooking temperature you want and set the selector switch to allow Bake, Broil, Timed Bake, and so on.
Many range/ovens have a light inside the oven. Sometimes a switch on the control panel lets you manually turn the light on. There's also usually a plunger-type of switch mounted to the frame of the stove that turns on the light when you open the door. Some units also have a rangetop light with a manual On/Off switch on the control panel.
The surface burner switches are also referred to as "infinite switches." They work in much the same way as a dimmer switch for a light in your home. By turning the switch from low to high you are increasing and decreasing the electrical current flowing through the electric burner thereby adjusting the temperature of the element.
Self-cleaning buttons or switches
In addition to the clock controls for the self-cleaning feature, there may also be other related devices--for example, a door lock button or switch, a separate switch to toggle between self clean and normal bake, etc. Because self-cleaning ovens differ, we can't explain every possible combination of devices needed to begin the self-cleaning cycle for your particular oven. We recommend that you consult your owner's manual for more information.
Convection oven components
Convection ovens use a circulating fan to constantly move the air inside the oven. This provides a very even cooking temperature throughout the oven. With the temperature consistent, foods cook more evenly and quickly. Some units incorporate the heating element into the circulating fan, which prevents the hot spots that can be caused by an exposed heating element. Other units put the heating element beneath the oven floor, or integrate it with the convection fan itself.
Convection ovens use a selector switch in conjunction with a thermostat, so that you can turn off the convection feature when you don't want it.
Electric range/ovens may have coil type burners on their cooktops--the top of the range/oven. Or the whole cooktop may be what's called a "smoothtop," where the burners are integrated with the top surface of the unit.
Coil type burners - The cooktop usually has four to six metal burners (or heating elements). Each is a coiled sheath with a wire in the center and no moving parts. When the wire receives electricity, the wire becomes red hot, which heats the metal sheath by conduction. Then the sheath glows red. You see this glowing when the element is turned on.
Euro type burners - Euro burners are solid, smooth, and 6 to 8 inches in diameter. Each has an internal coil of wire in the center and no moving parts. When the wire receives electricity, it becomes hot, which heats the solid metal surface. Although the surface of the burner doesn't glow bright red, it becomes very hot.
Smoothtop ranges - The way smoothtop ranges work is similar to the way coil type burners work. There is a coiled wire beneath each burner area. When electricity is applied to the wire, it glows red hot. The heat created is conducted through the glass and either radiated to the pan on the cooktop or conducted from the glass to the metal of the pan.
Some smoothtop ranges also have red halogen lights to supplement the coil-type elements. These get hot immediately, to speed the burner's warm-up time.
The area beneath the cooktop
Many cooktops with coil burners let you raise the entire cooktop for cleaning and service. Manufacturers often place the model and serial number tag for the appliance beneath the cooktop.
The racks inside the oven hold the food to be cooked. In most non-convection ovens, you can see the heating element at the bottom of the oven and the broiler element at the top. Each element is a coiled metal sheath with a wire in the center, and no moving parts. When electricity flows to the wire, the wire becomes red hot and heats the metal sheath by conduction. The sheath then glows red, which you can see shortly after you turn on the oven or broiler.
See "The interior of the oven."
Much of the wiring for an electric range/oven is on the back of the appliance. The steel panels that cover the wiring protect both you and the wiring. Other components--such as relays, self-cleaning switches, transformers, and terminal blocks--are also behind the protective back panels.
Gas combination range/ovens are stoves that have both surface burners and an oven. Depending on their features, some gas range/oven units are quite complex. To understand how they work, let's look at the following areas.
There are many variations of range/oven combination units. We'll describe the following controls and devices, their function, and the interaction they may have with other components.
In a non-electric oven system, the thermostat is right behind the knob you use to set the oven baking or broiling temperature. There's a long, thin copper tube attached to this thermostat that leads into the oven compartment. It senses the temperature inside the oven and signals the thermostat to provide or prevent further heating.
There's another type of thermostat--an electronic/mechanical hybrid unit--that has a small electronic circuit board behind the knob. It has a sensor attached to it--about the size of a 4- to 6-inch pencil, that protrudes into the oven. When the oven reaches the temperature you set, the sensor signals the circuit board, which turns off the gas burner(s) in the oven.
The clock is either electronic or mechanical:
Electronic clocks have a lighted, digital readout. These are not usually repairable; when they fail, you usually need to replace the whole clock.
Mechanical clocks usually have three dials--the clock dial, a Start time dial, and a Stop time dial. You set the main clock to the time of day. Then, when you choose a time-bake or self-clean cycle, the clock turns on the oven at the start time and turns it off at the stop time. The Start and Stop dials are for both timed baking and self-cleaning.
Some range/ovens have a keypad for setting all of the oven, broiler, timed bake, and self-cleaning times, and temperatures. These keypads can't be serviced; you usually need to replace them when a problem arises.
Selector switch for bake/broil/timed bake, etc.
Gas range/ovens have at least one control switch for the oven/broiler. On some units, this is the same switch as the thermostat, on others it is a separate switch.
If it's a separate switch, it works in conjunction with the thermostat. You set the thermostat to the cooking temperature you want and set the selector switch to allow Bake, Broil, Timed Bake, and so on.
Many range/ovens have a light inside the oven. Sometimes a switch on the control panel lets you manually turn the light on. There may be a plunger-type of switch mounted to the frame of the stove that turns on the light when you open the door. Some units also have a rangetop light with a manual On/Off switch on the control panel.
Self-cleaning buttons or switches
In addition to the clock controls for the self-cleaning feature, there may also be other related devices--for example, a door lock button or switch, a separate switch to toggle between self clean and normal bake, etc. Because self-cleaning ovens differ, we can't explain every possible combination of devices needed to begin the self-cleaning cycle for your particular oven. We recommend that you consult your owner's manual for more information.
Gas delivery (burner, oven, and broiler)
All gas range top burners use a similar system of gas delivery. There's one control knob for each burner. It's attached to a small gas valve that's mounted right to a main gas line. As you turn on the valve, the gas flows through the valve into a "venturi" tube, which mixes the gas with air to create the proper mix for combustion. The mixture then flows into the burner itself, where the standing pilot light flame or the igniter ignites it. You regulate the flame size by adjusting the burner control knob. It restricts the amount of gas that flows through the valve.
Often the oven and broiler work in a similar way. The thermostat knob may be attached to a small gas valve that's mounted right to a main gas line. As you turn on the valve, the gas flows through the valve into a tube that is then attached to a safety control valve. The safety control valve doesn't allow gas to flow through to the burner unless there is an ignition source available. The ignition may be provided by a standing pilot light flame or by an electric igniter. When the gas flows and ignites, the flame stays lit until the thermostat senses the proper temperature and shuts off the gas flow.
With a digitally controlled system, there's no need for a mechanical gas valve. Instead, the digital circuitry sends the signal straight to the safety valve. Then, if the electric igniter is working properly, the safety valve opens and sends the gas to the burner, and the hot igniter ignites it. The digital system uses a small electronic sensor inside the oven to sense the temperature. When the set temperature is reached, the circuitry sends a signal to turn the safety valve off, which stops the flow of gas. When the oven temperature cools slightly, the sensor again sends a signal to the circuit board, which re-lights the burner.
The area beneath the cooktop
Many cooktops that have non-sealed gas burners let you raise the cooktop for cleaning and service. Many manufacturers often also place the model and serial number tag for the appliance beneath the cooktop. In addition, the individual burner gas valves and ignition components may be located here.
The rack inside the oven holds the food to be cooked. The interior light bulb, the thermostat sensor, and, in some units the broiler components, are also located here.
The area behind the broiler drawer
This is where the safety valve, spark igniter, fuse, and other components are often located.
Much of the wiring for a gas range/oven is located on the back of the appliance. The steel panels that cover the wiring protect both you and the wiring. Other components--such as relays, self-cleaning switches, transformers, and terminal blocks--are also behind the protective back panels.