Ultimate Fix-It-Yourself Manual: Large appliances--Ranges / gas

Gas ranges have few moving parts and are generally easy to repair. In older models that lack electrical parts, the burners are ignited by a continuously burning pilot flame. In newer models, the surface burners are lighted by electronic igniters that spark or heat a metal coil; the oven burners are lighted by igniters or electrically heated ceramic bars called glow-bars.

For maximum efficiency, the burners must be clean and the flames must contain gas and air in the correct proportion. A proper flame burns steadily and quietly, and displays sharply defined blue cones about ½ to ¾ inch in height. Too much air produces a noisy, unsteady flame that may not completely encircle the burner and can result in erratic ignition. Too little air results in a weak, sooty flame with no blue cones.

Gas ranges must be adjusted for either liquid propane (LP) or natural gas. If you want to change the type of gas your range uses, call the gas company.

Call the gas company also for any repairs involving the gas supply line or burner gas-control valves. Incorrect repairs to these parts can create hazardous gas leaks. Repairing accessories like a clock or an appliance receptacle, and purely mechanical parts such as oven door hinges and gaskets, is the same as for an electric range.

Components include:

• Clock-timer
• Oven thermostat
• Surface burner
• Flash tube
• Electric igniter
• Thermostat sensing tube
• Oven light
• Air shutter
• Burner gas valve
• Burner igniter switch
• Glowbar
• Glowbar
• Oven burner
• Door hinge and spring
• Oven selector switch
• Oven vent
• Thermal cutoff
• Grate
• Door latch (self-cleaning oven)
• Door gasket

Note: Details of repair and disassembly may vary, depending on appliance model. If your gas range differs markedly from this one, see Appliance repair basics, for electrical repairs. Have a gas-related problem serviced professionally.

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FOR YOUR SAFETY

Shut off the gas supply before working on a range. The gas supply valve is usually located behind the range, and is off when the valve handle is perpendicular to the pipe. Don’t move a range wit/i a rigid gas supply pipe. Call the gas company or a professional. Unplug the power cord before working on the electric ignition or other electrical parts of a gas range. If you smell a taint gas odor, check for a surface or oven pilot flame that’s out or a burner that’s on and unlighted. Air out the room, wait 5 minutes, and relight the pilot. If this fails, have the gas company check the supply line.

If there’s a strong gas odor, open windows and doors, and evacuate everyone. Don’t light a fire, flip a switch, or use a phone. Call the gas company from a neighbor’s house.

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Gaining access:

To remove surface burners, lift cooktop. Pull burners up and off valve. Burner configurations vary greatly.

To reach lower oven burner, remove oven door. Re lease rear clips and lift out oven bottom and any burner cover.

To reach rear accessories and controls, take out top and bottom screws in ends of control panel; roll panel onto a towel.

To open front control panel, open cooktop. Pull off knobs, remove top and bottom screws, and lift off front.

Troubleshooting:

[Degree of difficulty: Simple---Average---Complex---Volt-ohm meter required]

Adjusting and cleaning cooktop burners:

Air shutters on the burner tubes regulate the gas-air mixture. Adjusting them and cleaning the burners will fix most burner problems. If a burner won’t light, check the pilot or electronic ignition. Be careful working around open flames.

To adjust air shutter, lift cooktop and loosen shutter adjusting screw. Turn burner on High and open shutter until flame is noisy and unsteady. Then close shutter slowly to produce steady flame with sharp blue cones. Retighten screw.

To clean burners, lift cooktop and remove burner unit. Open clogged flame openings with a toothpick, flash tube ports with a fine wire. Wash in hot soapy water with soft brush; rinse. Swab inside of flash tube. Let dry.

Adjusting and cleaning cooktop pilots:

Adjust pilot flame by turning adjustment screw on pilot gas supply line.

Turn the screw counter clockwise on most ranges to increase the flame. Correct flame is a sharp blue cone, 1/4 to 3/8 in. high.

Clean pilot orifice if it's plugged. Remove shield, if any, around orifice and wipe orifice with dry lint- free cloth. Clean opening with pin or toothpick, taking care not to enlarge or deform opening.

Replacing electronic spark igniters and controls:

Each igniter serves two burners. If a burner doesn’t light, try the companion burner. If it works, the first burner’s switch is likely faulty. If neither burner works, clean the electrode with a soft cloth. Check for loose connections on the ignition control module on the back of the range. If no igniters work, suspect a faulty module. The switches for all the burners are usually wired together; replacements are sold as a unit. CAUTION: Unplug the range before testing or fixing electronic ignition parts.

To replace igniter, unscrew bracket and clip off electrode and bracket. Tape end of new igniter wire securely to old wire, and pull new wire to control module on back of range.

To test igniter switch, slip it oft gas valve. Note how to set the switch on Lite, infinity on Off. Then trace its leads to the harness plug and control module on the back of the range.

On back of range, remove switch lead from module and disconnect harness plug. With VOM on RX1, probe lead and terminal in plug. Look tor zero reading with switch on Lite, infinity on Off.

Replace control module on back of range it no igniters work. Label and disconnect igniter wires; remove module from mounting bracket. Install identical new module.

Oven burners and thermal cutoff:

A clogged oven burner produces an uneven flame that can affect baking and cause a gas odor when you turn it on. High hissing flames indicate an air-gas mix with too much air; yellowish flames, too little. Suspect a faulty thermal cutoff if the burners go off after the oven has been on for a long time at a high setting. CAUTION: Never clean or adjust an oven burner while it’s on. After you fix it, turn it on to check the results.

Clean clogged burner ports with a tooth pick or a wire. It ports are rusty or grease- caked, go over them with a soft-bristle wire brush. Or remove burners and spray ports with auto degreaser; then rinse well.

To adjust oven air shutter, loosen screw on shutter and open or close it to obtain steady blue flames 1 in. long with distinct inner cones. Make adjustments with burner oft; light oven to check results.

To test thermal cutoff, open cooktop. Lift out burners; unscrew metal shield beneath. Remove a lead from cutoff. Probe both terminals with VOM on RX1. Look tor zero reading. If reading is infinity, replace cutoff.

Testing and replacing oven glow-bars:

On many ranges, the oven burners are lighted by electrically heated glowbars. Some glowbars snap into position, but many have a wire that goes to a plug on the rear of the range. The plug for the bake burner’s glowbar may be behind a small access panel.

(top): 1. Trace glowbar’s leads to harness plug on back of range, and disconnect plug. With VOM on RX1, probe terminals in plug. Look for moderate resistance, indicating significant continuity. CAUTION: Unplug range before testing glowbars. Use only the special heat- resistant wiring supplied with a replacement. (above): 2. To replace faulty glowbar, tie a string to the plug end of cord on the back of the range. Then inside oven, dismount glowbar and pull cord and string into the oven. Use the string to guide the installation of an identical replacement.

To adjust oven pilot, remove oven bottom. Slowly turn adjusting screw on safety valve to produce a steady blue flame with a yellow tip (or distinct inner core) about ¼ in. high. (On some models, adjusting screw is under thermostat knob.)

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