Monday, 13 March 2017

Replacing Oven and Broiler Heating Elements



Replacing Oven and Broiler Heating Elements
To remove an oven or broiler heating element, remove the screws or pull the plugs that connect it. Remove a retaining shield and lift out the element.
To remove an oven or broiler heating element, remove the screws or pull the plugs that connect it. Remove a retaining shield and lift out the element.













Electric oven and broiler elements are often even easier to test and replace than range elements. Here's how:
Step 1: If the oven element doesn't work, first check to see if the range is receiving power. Don't overlook the fusing system inside the range.
Step 2: If the range is receiving power, set the timer on the range to the MANUAL position.
Step 3: If the element still doesn't heat, turn off the power to the range and test it with a VOM set to the RX1 scale.
Step 4: Remove the screws or plugs that connect the element to the power. Remove the retaining shield, which is usually held by two screws, and remove the element from the brackets that hold it in the oven. The element is usually held in these brackets by screws.
Electric ranges and ovens use Nichrome elements to supply heat. Most malfunctions involve faulty heating elements.
Electric ranges and ovens use Nichrome elements to supply heat. Most malfunctions involve faulty heating elements.
Step 5: Clip the probes of the VOM to each element terminal. If the element is in working order, the meter will read from 15 to 30 ohms. If the meter reads higher than 30 ohms, the element is faulty and should be replaced. If the element tests all right but doesn't work, the problem may be at the terminals. Make sure the terminals are clean and tight at the element connections.
Oven and broiler elements cannot be tested without a VOM. If you don't have a VOM, take the element to a professional service person for testing. The problem is usually a malfunctioning element; however, you aren't risking much by replacing the element without a professional test.
Step 6: Take the burned out element with you to the appliance-parts store to make sure you get the right replacement part; if possible, take the make and model information, too.
To install the new element, place it in the same position as the old one. Connect it the same way the old one was connected, using the same screws to hold it in place. Just about all the other components of an electric range or oven (including its door gasket, oven controls, and timer) are virtually the same as the components used on gas ranges.
Most problems with gas and electric ovens or ranges are easier to fix than you think. The key is knowing how the various parts work and when to replace them.

Replacing Range Heating Elements


Replacing Range Heating Elements
TO REMOVE A RANGE HEATING ELEMENT, REMOVE THE SCREWS HOLDING THE TERMINAL
When a range heating element burns out, it's easy to replace. But before you disassemble the range to check or replace an element, make sure the range is receiving power. Here's what you can do:
Step 1: Check the power cord, the plug, and the outlet. Then look for blown fuses or tripped circuit breakers at the main entrance panel or at a separate panel.
Step 2: Check the fusing system inside the range. If the circuit is broken, restore it. If the range is receiving power, go on to check the element.
Step 3: When the element is cool, remove it. In most ranges, each top heating element is connected to a terminal block in the side of the element well. To remove the terminal block, lift the element and remove the metal drip pan that rests below it. The element is held by two retaining screws or is push-fit into the terminal block. To remove a screw-type element, remove the screws holding the wires. To remove a push-type element, pull the element straight out of its connection.
Step 4: Test the element with a volt-ohm-milliammeter (VOM) set to the RX1 scale. Disconnect one of the electrical leads to the element and clip one probe of the VOM to each element terminal. If the element is functioning properly, the meter will read between 40 and 125 ohms; if the meter reads extremely high, the element is faulty and should be replaced.
To test a range element without using a VOM, remove a working element from its terminal block and connect it to the malfunctioning element terminal. Don't let the test element overlap the edges of the element well; keep the element inside the well, even if it doesn't fit perfectly. Turn on the power to the range. If the working element heats, the suspected element is bad and should be replaced. If the working element doesn't heat, the terminal block wiring or the switch that controls the element may be faulty. Call a professional service person.
Step 5: Replace a burned-out range element with a new one made specifically for the range. Take the old element to the appliance-parts store; if possible, take the make and model information, too. This data will probably be on a metal tag attached to the back service panel of the range. To install the new element, connect it the same way the old one was connected.

Servicing Fuses

Servicing Fuses

If the range or oven is receiving power but doesn't work, the unit may have its own fuse or circuit breaker assembly. This assembly is usually located under the cooktop of the range. In some units, lift the top of the range to gain access to the fuse assembly; or lift the elements, remove the drip pans, and look on the sides of the cabinets. Inside the oven, look to the back to spot the fuse assembly.
If the unit has this additional fuse or breaker system, components such as the oven light, the range heating elements, the timer, and a self-cleaning feature may be separately fused.
If these components or features fail to work, don't overlook the possibility that the fuses have blown. To replace a blown fuse, unscrew the old fuse and install a new one of the same type and electrical rating. If the unit has circuit breakers, push the breaker or reset button, which is usually located on the control panel.

Electric Oven: Repairs and Maintenance

Electric Oven: Repairs and Maintenance
Electric ranges and ovens are generally easy to repair, because there's not much to go wrong and there's not much you can do. Most repairs are actually replacements, a matter of unplugging the old part and plugging in the new. Most of the malfunctions that affect electric ranges involve faulty heating elements.
Caution: Before doing any work on an electric range or oven, make sure it's unplugged, or turn off the power to the unit by removing one or more fuses or tripping one or more breakers at the main entrance panel or at a separate panel. If the range is fused at a separate panel, this panel may be located adjacent to the main panel or in a basement, crawl space, or other location. If there is a grounding wire to the range, disconnect it. Make sure the power to the unit is off.

Gas Oven: Pilot Lights, Shutoff Valves, and Ignition Systems


Gas Oven: Pilot Lights, Shutoff Valves, and Ignition Systems
The flame of a gas range burner should be steady and slightly rounded, with a light-blue tip. To adjust the flame, slide the air shutter mixer plate open or closed.
The flame of a gas range burner should be steady and slightly rounded, with a light-blue tip. To adjust the flame, slide the air shutter mixer plate open or closed.
The flame of gas range burners should be steady and slightly rounded, with a light-blue tip. The flame should be quiet and should respond to adjustments made at the control knobs. Most burner troubles can be quickly solved by adjusting the air shutter mixer plate, which is located at the end of the burner tube near the knob controls. Turn a small screw on the plate, slide the plate open or closed, and tighten the setscrew.If the flame is yellow, it's not receiving enough air. To allow more air in, open the plate slightly. If the flame is high or makes a roaring noise, it's getting too much air and you should close the plate slightly.

Servicing Pilot Lights

The oven pilot is usually located at the back of the oven; turn a screw on the pilot ignition unit to adjust the pilot flame height.
The oven pilot is usually located at the back of the oven; turn a screw on the pilot ignition unit to adjust the pilot flame height.

One pilot light usually serves all the top burners of a gas range. Some ranges have two pilot lights, one for each side of the range. A correctly adjusted pilot flame is steady and blue, between 1/4 and 1/2 inch high. If the flame goes out repeatedly, or if it's yellow at the tip, it's getting too little air. If there's a space between the flame and the pilot feed tube, it's getting too much air. To correct either condition, turn the pilot adjustment screw on the gas line slightly, as directed by the manufacturer of the range.
Most modern gas ranges use an electronic pilot igniter to start the pilot.
If the pilot flame is properly adjusted, but the flame doesn't ignite the burners, the problem is probably in the flash tubes that run from the pilot to the burners. These tubes may be blocked by spilled food from the burners. If this is the case, turn off the power to the range and clean out the tubes using a short piece of wire. Push the wire through the opening until the tube is clear. You may have to disconnect the tube to clear it. After cleaning the tube, replace it in the same position.
If the pilot has a switch, the switch may be faulty. Turn off the power to the range and test the switch with a volt-ohm-milliammeter (VOM) set to the RX1 scale. Remove the retaining screws that hold the switch in the range cabinet, and disconnect both electrical lead wires to the switch. Clip one probe of the VOM to each switch terminal. If the switch is functioning, the meter will register zero. If the meter reads higher than zero, the switch is faulty and should be replaced. Remove the switch and replace it with a new one of the same type. Connect the new switch the same way the old one was connected.
Most newer gas ranges and ovens don't have pilot lights. Instead, the gas is ignited by an electric ignition system. In this type of system, an element becomes hot and glows like the filament in a lightbulb when an electric current passes through it. The heat from the filament lights the gas. As a rule, these ignition systems are sealed and cannot be repaired or adjusted. When an electric ignition device fails, don't try to fix it. Call a professional service person for replacement.
If the flame is set too low, adjust it. Next to the pilot, locate a small boxlike unit with a couple of screws in it. This is the ignition unit. The ignition unit could also be located below the pilot; follow the gas line down until you locate it. Turn one of the screws on the ignition. Experiment, turning the screws a little at a time, until the flame is adjusted properly. It should not be as high as the top pilot flame; leave it as low as possible. On some oven pilots, turn the control to the OFF position and light the pilot; then turn the oven dial to the BROIL position. The pilot will heat the controls to the ignition switch.

Servicing Automatic Shutoff Valves

On some ranges, there is an automatic shutoff valve located in the pilot assembly that shuts off the gas to the burner any time the pilot and the burner are both off. If this unit malfunctions, don't try to fix it yourself; you should call a professional service person for repair or replacement.An electrically operated shutoff valve used on some gas ranges has two facing valves, an electromagnet, and a manually activated reset button. The thermocouple fitting is next to the pilot valve, as in most burner systems. A small amount of electricity holds the facing valves apart. If the pilot light goes out, no electricity is generated, and the valve closes to turn the gas off. On this type of system, relight the pilot by depressing the reset button and holding a match to the pilot. It should take about a minute to light this pilot. If you aren't able to relight this system, call a professional service person.Electric ovens and ranges are growing in popularity, probably because most repairs involve simply replacing a worn or faulty part. Learn more about how to provide routine maintenance for an electric range in the next section.

Replacing the Timer



Replacing the Timer
The range timer is usually located in the control panel on top of the range.
If you suspect the timer is faulty, don't try to fix it yourself.
Remove it and take it to a professional service person for testing.
Here's how to remove the timer:
Step 1: Remove the back service panel to the control panel and release
the spring clips that hold it in position, or remove the retaining screws.
Step 2: Push the timer forward to release it.
Step 3: Remove the electrical lead wires from the timer housing.
If, when disassembling the timer, you notice that the electrical wire terminals look burned, remove these leads and buff the leads and the terminal points with fine steel wool. Burned and/or dirty terminals can cause the timer to malfunction, but a good cleaning can solve this problem.
Step 4: Replace the old timer or install a new one of the same size and type, if this is necessary. Connect the new timer the same way the old one was connected.
The flame color on a gas range burner can give you a clue if any burner troubles exist. In the next section, learn what those clues mean and what to do about them.

Servicing Oven Thermostats

Servicing Oven Thermostats

If the oven doesn't heat evenly or doesn't heat at all, the oven thermostat may be malfunctioning. First, determine how much the temperature in the oven is off from the control setting. To do this, put an oven thermometer on a center rack inside the oven and turn the oven on for about 20 minutes, with the thermostat set at any range between 300 degrees and 400 degrees Farenheit. If the oven thermometer reads 25 degrees or more lower or higher than the oven control setting, the thermostat should be recalibrated. Here's how to calibrate the thermostat:
Step 1: Pull off the thermostat knob on the control panel. Behind the knob are two screws holding a round, notched plate. Loosen these screws, but do not remove them.
Step 2: With a screwdriver, change the notch setting on the notched plate by turning the plate counterclockwise; for every eighth of a turn, the oven temperature goes up about 25 degrees Farenheit. To turn the heat down, turn the plate clockwise.
Some thermostats can be adjusted by turning a screw inside the control knob shaft housing. To do so, remove the knob and insert a screwdriver into the shaft so that the screwdriver blade engages a screw slot. Turn the screwdriver counterclockwise about one-eighth of a turn to raise the heat about 25 degrees Farenheit. Here's how to test a malfunctioning thermostat:
Step 1: Test the thermostat with a VOM (multimeter) set to the RX1 scale. The thermostat is located directly on the back of the control knob that regulates the heat. To gain access to the thermostat, remove the back service panel to the control panel.
Step 2: Disconnect one electrical lead wire from a terminal of the thermostat and clip one probe of the VOM to each thermostat terminal. If the thermostat is in working order, the meter will register zero. If the needle jumps to a higher reading, the thermostat is faulty and should be replaced.
Step 3: If necessary, replace the thermostat with a new one of the same type.
If you need to replace the thermostat, follow these guidelines:
Step 1: Disconnect the terminal wires to the thermostat and pull off the control knob.
Step 2: Remove the retaining screws. On some ranges, there is a wire running from the thermostat into the oven. This wire operates a sensing bulb that controls the thermostat. The sensing bulb is usually held by a bracket; unscrew this bracket to remove the bulb. Then carefully slip out the wire, the bulb, and the thermostat.
Step 3: Install the new thermostat using a reverse procedure.