Fix-it-Yourself--Major Appliances: GAS RANGES

A gas range has few moving parts, and many older machines have no electrical parts at all. The two basic types of gas ranges differ mainly in the way they ignite the gas. In older models, gas flows to the range and oven burners and is ignited along the way by a small pilot light. Ranges with electric igniters use sparks or an electrically heated coil called a glowbar to ignite the gas. The igniters are wired to an ignition module on the back of the range that produces the high voltage required for sparking. On both types, air shutters control the amount of air mixed with the gas flowing to the burner. A thermostat regulates oven temperature by turning the gas on and off.

Most gas ranges have similar components, and the repairs on the following pages can be adapted to older and newer models alike. Most problems are caused by dirt—spilled food often clogs burner portholes and grease can block air shutters. Clean often under the cooktop and wash the burners as needed.

Repairs that involve the gas supply line, such as replacing a burner control or a thermostat, carry the risk of creating gas leaks and should always be left to a professional. If the supply line is a rigid pipe, never move the range; have the gas company or a service technician disconnect and move it for you. Make sure you know the location of the gas shutoff valve for your range, and how to turn it off; it’s usually on the supply pipe behind the range (140).

Some gas range repairs—replacing a clock or gasket, or adjusting an oven door—are the same as for electric ranges. If a repair is not listed here, consult the electric range Troubleshooting Guide (43).

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Gas supply pipe

The shutoff valve is usually located on this pipe. Some ranges have a flexible gas line that allows the range to be moved for cleaning or repair. Don’t move a gas range with a rigid pipe.

Flash tube

Gas that enters the burner is ignited here.

Burner pilot

Ignites the gas. The pilot can go out when the tiny orifice becomes blocked by grease or dust. In some ranges, this is replaced by an electric spark igniter.

Thermostat capillary tube

Senses oven temperature.

Gasket

A rubber seal around the oven door helps regulate air flow in the oven.

Burner air shutter

A valve on the surface and oven burners that controls the amount of air mixed with the gas flowing to the burner. The oven air shutter can become clogged with dust and should be cleaned frequently.

Safety valve

Prevents the flow of gas to the oven burner if the pilot or electric igniter is off.

Oven vent

Never block this vent, which allows heated air to escape from the oven for proper temperature control.

Internal plug

Surface burner

Distributes flame evenly. Should be cleaned frequently to prevent the portholes from becoming clogged.

Cooktop

In most ranges, can be lifted for cleaning and access to the surface burners.

Oven thermostat

Controls the temperature within - the oven by turning the gas on and off.

Burner valve

Manifold

This pipe runs beneath the — range top across the front, carrying gas to the burners and oven.

Oven pilot

Ignites the gas. When the oven is turned on, the pilot heats a -- sensing bulb connected to the safety valve, which releases gas to the burner. In some ovens, this is replaced by an electric glowbar or spark igniter.

Broiler drawer

Allows food to be broiled under the oven burner. Can be removed when relighting the oven pilot. Poor fit can be adjusted by loosening and retightening the screws on the inside of the door.

Clock and timer

Burner grate

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TROUBLESHOOTING GUIDE

ACCESS TO THE RANGE

Opening the cooktop. To reach the surface burners and pilots or electric igniters, remove the burner grates, grasp the front edge of the cooktop or the two front burner wells, and lift. Prop the cooktop open with the support rod inside. To replace the cooktop, lift it off the support rod and lower it gently; lowering it too rapidly can blow out the pilot lights. On some ranges, the cooktop can be removed completely by lifting it and pulling it toward you.

Disconnecting an internal range plug. In gas ranges with electrical components—clock, lights, ignition system—an internal harness plug connects the power cord to the internal wiring. You can disconnect power to the range by unplugging this assembly. Raise the cooktop (left), locate the plug (usually at the right rear of the machine) and pull to disconnect it. Examine the plug for burned or pushed-in terminals (above). Reposition the terminals by hand if you can, and reconnect the plug. If the components still don’t work, or if the terminals are burned, replace the plug: Cut the wires, splice on the wires of a replacement plug (136) and reconnect the plug.

Removing the oven door. Most newer ranges have a removable oven door, simplifying access to the oven burner assembly and pilot light or electric igniter. To remove the door, open it to the first stop, the broil position, and grip each side. Supporting the door with your knee, pull it up straight off its hinges. The spring-mounted hinge arms can slam shut against the range if accidentally touched; you may close them against the cabinet for safety.

Removing the oven bottom and baffle. On many ranges you can simply lift out the oven bottom. For some models, you must first slide forward small locking tabs at the front or rear of the oven bottom. If screws hold the oven bottom in place, loosen them slightly and slide them back to release the bottom. To replace a broken or corroded oven bottom, reverse these steps. To remove the oven burner baffle beneath the oven bottom, remove the wing nut or screws holding it in place. Then lift it up and out (inset).

LIGHTING AND ADJUSTING SURFACE BURNER PILOTS

Relighting a surface burner pilot. Caution: If the pilot has been out for some time, or you detect a strong odor of gas, ventilate the room and call for service (12). Otherwise, turn off all range controls and prop open the cooktop (62). Place a lighted match near the opening of the pilot, located midway between two burners, as shown. If the pilot does not stay lit, clean it (below, left) or adjust it (below, right).

Cleaning a pilot. The small opening of a pilot can easily become clogged with dust, grease or food, preventing proper gas flow to the pilot light. A pilot that won’t light, or won’t stay lit, may simply need cleaning. Insert a sharp wooden toothpick in the pilot opening, as shown, and move it up and down gently, taking care not to enlarge or deform the opening. If a protective metal shield over the pilot prevents you from reaching the opening, remove it by pressing in the tabs on either side. Clean an oven burner pilot the same way.

Adjusting the pilot height. A pilot that frequently blows out may be set too low or too high. To adjust it, turn oft the controls and prop open the cooktop (62). The pilot adjustment screw is usually on the side of the pilot, or on the pilot gas line near the manifold at the front of the range. (On some ranges, the adjustment screw is behind the burner control knob. Pull off the knob and insert a screwdriver into the opening beside the stem to adjust the pilot.) Using a screwdriver, turn the screw slowly counterclockwise to increase the size of the pilot light, as shown. The flame should be a sharp blue cone, 1/4 to 3/8 inch in height. Replace the cooktop when the pilot is properly adjusted.

CLEANING AND ADJUSTING SURFACE BURNERS

Cleaning the burner portholes. If a burner won’t light, raise the cooktop (62) and check that the pilot light (63) or spark igniter (65) is working. Also, check that the burner is properly seated on its support—the flash tube should form a straight line from the pilot or spark igniter to the burner portholes. If the portholes are clogged, gas cannot flow into the flash tube for ignition. Use a needle or fine wire—or even a straightened paper clip—to ream out the burner portholes opposite the flash tube, as shown.

Removing a surface burner. On most ranges, the surface burners are designed to be removed easily for cleaning. On some older ranges, only the top ring of the burner comes off; the burner base remains in place. Prop open the cooktop (62). Lift the burner from its sup port, then pull the burner tube backward off the burner valve, as shown. If the surface burners were screwed to the supports for ship ping, discard the screws; they can cause the burners to warp out of alignment with the flash tubes. Wash the burner in hot, soapy water, and scrub the portholes with a brush. After washing, use a pin or wire to clean the flame openings (inset). Let the burner dry thoroughly. To replace the burner, insert the tube onto the burner valve and lower the burner onto its support.

Adjusting a surface burner air shutter. A shutter or sleeve on the burner tube controls the amount of air that mixes with the gas flowing to the burner. An improper gas/air mixture results in an inefficient flame (right). To adjust the air shutter, turn off all controls and raise the cooktop (62). Locate the air shutter-on the burner tube near the manifold at the front of the range—and loosen the screw holding it in place. Turn the burner control on HIGH and twist or slide the shutter open, as shown, until the flame is fed excessive air. Slowly close the shutter until the flame is the correct size and color. Turn off the burner control, tighten the shutter screw and replace the cooktop. On models with an air-mixing chamber, loosen the retaining screw, slide the plate to adjust the air intake and tighten the screw.

Insufficient air--Not enough air results in a weak flame without sharp blue cones. The flame may be red, yellow or yellow-tipped, and may leave soot deposits on pots and pans.

Excessive air--An unsteady, blowing flame is a sign of too much air. The flame may not burn all around and may be noisy. Too much air can also prevent the burner from igniting.

Correct air adjustment--A properly adjusted burner has a steady, quiet flame with sharply defined blue cones about 1/2 to 3/4 inch in height.

SERVICING THE ELECTRIC IGNITER

1. Checking the electric igniter. If a burner won’t light, raise the cooktop (62) and observe the igniter as you turn on the burner. If it doesn’t spark, turn on the second burner; if the niter now works, the first burner control is faulty; call for service. If the second burner doesn’t work, the igniter or the ignition control module may be at fault. Unscrew the bracket over the igniter and inspect it; replace the igniter if cracked or burned (step 2). If the igniter is dirty, clean it gently with a cotton swab or clean rag, as shown, and check it again. Replace the ignition control module if no igniters work (step 4).

Disconnecting the electric igniter. Electric igniters are wired to an ignition control module that produces high voltage for the spark. Turn off power to the range by disconnecting the plug under the cooktop (62), or by unplugging the range from the outlet. (Caution: If the gas supply line is a rigid pipe, don’t attempt to move the range.) Pull the range away from the wall and trace the cable from the igniter to the module, a plastic or metal box mounted on the back of the range (in some models, it’s underneath the oven bottom). With a screwdriver, remove the metal plate covering the module. Pull the igniter cable from the module terminal, as shown.

3 Replacing the igniter. Unscrew the bracket over the igniter. The cable may also be fastened with clips to the underside of the burner support; remove the clips. Pull the igniter cable through the hole in the burner support, as shown. To simplify threading the new cable, tie a string to the end of the old one and pull it through the range as you pull out the cable. Tie the string to the end of the new cable and pull it back through to the module. Seat the igniter firmly on the burner support. Connect the new cable to the ignition module and replace the module cover.

Replacing the ignition control module. Locate and uncover the ignition control module (step 2). Use masking tape to label the positions of all the wires leading to the module, then disconnect them. Unscrew the module from the range. To install a new module, first screw it to the range, then reconnect the wires and replace the cover plate. Push the range back against the wall, turn on the power and check the operation of the burners.

LIGHTING AND ADJUSTING THE OVEN PILOT

Relighting the oven pilot. Turn off all the range controls. If your range is equipped with a broiler drawer, open it and wait five minutes for gas to dissipate. To light the pilot, reach back with a lighted match to the tip of the pilot on the burner assembly (near left). Otherwise, open the oven door and remove the oven bottom and baffle (62). Place a lighted match near the tip of the pilot on the burner assembly(far left). On some older ranges, you must hold down a button on the side of the oven or on the oven thermostat as you light the pilot. Replace the baffle and oven bottom. Turn on the oven and wait a minute or two for the burner to light; if it doesn’t, adjust the pilot (next step).

Adjusting the oven pilot. If the oven pilot flame is set too low, the burner won’t light even if the pilot is on. To adjust the pilot, turn oft all controls and remove the oven bottom and baffle (62). Examine the safety valve on the burner assembly at the rear of the oven for a slotted screw near the gas line to the pilot. (If the adjustment screw is not on the safety valve, proceed to the next step). With a screwdriver, turn the screw counterclockwise in tiny increments, as shown, until the pilot has a steady, blue, yellow-tipped flame about 1/4-inch high. If the pilot won’t light, turn the screw slightly, then light the pilot. Turn on the oven thermostat and observe the burner and pilot. If the pilot flame does not increase, the thermostat is probably defective. If the burner does not light within four minutes, the safety valve must be replaced. In either case, call for service.

Adjusting the oven pilot at the thermostat. Pull off the oven temperature control knob and check for a slotted screw (sometimes marked “Pilot” or “P”). If you can’t find the screw at the front of the thermostat, raise the cooktop (62) and inspect the back of the thermostat for a slotted screw near the gas line to the oven pilot. Turn off all controls, open the oven door and remove the oven bottom and baffle (62). Adjust the pilot flame as described in the previous step; check for the same results and call for service it necessary. Gently push the control knob back on its shaft or lower the cooktop.

CLEANING AND ADJUSTING THE OVEN BURNER

Cleaning the oven burner. Poor baking results, or an odor of gas when the oven is on, may be due to the uneven flame produced by a clogged burner. With all controls off, remove the oven door and take out the oven bottom and baffle (62). Turn on the oven and observe the burner. If the flame is not continuous along the length of the burner, some of its holes may be clogged. Turn off the oven control. Poke a thin, stiff wire or a needle into each hole in the sides of the burner, as shown, and rotate it to clear the blockage.

Adjusting the oven burner flame. With all controls off, remove the oven door, oven bottom and baffle (62). Locate the air shutter at the base of the oven burner, just above the safety valve. Loosen the shutter screw and rotate the air shutter to increase or decrease the shutter opening (above, left); the larger the air opening, the larger the flame. Some older ranges have an air-mixing chamber with a sliding plate that controls the size f the air opening; loosen the screw and slide the plate. Remove your hand from the oven and turn on the oven temperature control to observe the flame. If it’s not the proper size (above, right) and color, turn off the oven and readjust the air shutter. When the flame is correct, tighten the shutter screw and replace the baffle and oven bottom.

CHECKING AND REPLACING THE OVEN FLAME SWITCH

1 Removing the flame switch. In some gas ranges, an oven flame switch pre vents gas flow to the burner if the pilot goes out. If the pilot is lit but the oven burner doesn’t ignite, the problem may be a faulty flame switch. Disconnect the plug at the rear (62). Remove the oven door, the oven bottom and the baffle (62). Remove the screws holding the flame switch to the oven wall and pull it forward, as shown.

2 Testing the flame switch. Disconnect the two wires from the flame switch terminals at the back, but don’t re move the wire in the front that leads to the sensing bulb. Clip one probe of a continuity tester or a multitester set at RX1 to each terminal and test for continuity. If the tester does not show continuity with the oven pilot lit, replace the switch. If the switch has continuity, the oven thermostat is probably faulty; call for service.

3 Replacing the flame switch. To remove a defective flame switch, gently work the pilot-sensing bulb loose from its bracket near the pilot. The bulb may contain mercury; take care not to break it. To install a new flame switch, replace the pilot- sensing bulb in its bracket, reconnect the two wires to the new switch and screw the switch to the oven wall. Replace the oven bottom, baffle and door.

CHECKING AND REPLACING THE OVEN ELECTRIC IGNITER

1 Checking the oven spark igniter. When the oven thermostat is turned on, the igniter spark lights the pilot flame, which heats a sensing bulb connected to the safety valve. At a certain temperature, the safety valve opens and gas flows to the burner, where it’s ignited. If your oven won’t light, first check the igniter. Turn off power to the range and remove the oven door, bottom and baffle (62). Unscrew the igniter from its mounting bracket and inspect it for cracks or other flaws, as shown. Replace the igniter if damaged.

2 Replacing the oven spark igniter. The igniter is connected to the ignition control module, which is usually mounted on the back of the range; in some models it’s under the oven bottom. Pull the range away from the wall. (Caution: Don’t move the range it its gas supply line is a rigid pipe.) Trace the igniter cable to the module and unscrew its cover plate. To help you thread the cable, use a string (65). Disconnect the igniter cable from the module and pull the igniter and cable out through the oven. Screw the new igniter to the bracket with its electrode 1/4 inch from the pilot. Thread the cable through the back of the oven and connect it to the ignition module.

TESTING AND REPLACING THE OVEN GLOWBAR IGNITER

1 Testing the fuse. If your oven does not heat, check its cartridge fuse with a continuity tester or a multitester set at RX1. Raise the cooktop and disconnect the internal range plug (62). The fuse is near the safety valve, in a metal cover or fuse holder; reach it by removing the broiler drawer or the oven bottom (62). (For a self-cleaning range, unscrew the access panel below the oven door and the metal heat shield inside.) Unscrew the fuse cover or the top of the fuse holder. Disconnect one of the wires to the fuse and touch a tester probe to each terminal, as shown. If the fuse is difficult to test in place, use a plastic fuse puller to remove it for testing. If the tester does not show continuity, replace the fuse with one of the same amperage and screw the metal fuse cover back in place.

2 Checking the glowbar. First make sure the clock timer is set properly. Turn on the thermostat; if the indicator light does not come on, call for service. To check the glowbar, turn off power to the range and pull it away from the wall. (Caution: Don’t move your range if its gas supply line is a rigid pipe.) At the back of the range, unscrew the cover plate over the glowbar wiring and disconnect the plugs, as shown. In some ranges, the glowbar wiring is under a metal cover near the oven burner assembly; in this case, remove the oven door and the oven bottom and baffle (62). Insert a continuity tester probe into each glowbar terminal; if the tester does not show continuity, replace the glowbar. If the glowbar has continuity, the safety valve may l faulty; call for service.

3. Replacing the oven glowbar. Unscrew the glowbar from the burner support bracket and the oven wall, and pull the glowbar free, as shown. Mount a new glowbar in the burner support bracket at the back of the range, reconnect its plugs at the back of the range and replace the metal cover over the glowbar wiring.