There are a number of reasons that the pilot light on a gas appliance goes out; a stiff breeze may have blown out the flame, an interruption in gas service may have stopped the gas supply or there could be a problem with the pilot tube or thermocouple. Identifying the problem is the first step in repairing your appliance and may save you money on a technician or unnecessary repairs. After some basic troubleshooting, there are a few repairs that may help to keep the pilot light on, such as ensuring the pilot is protected from drafts, cleaning the pilot tube and changing the thermocouple.
Turn off the gas to the appliance by turning the gas knob to be perpendicular to the gas line. Leave the area for 10 to 15 minutes while the gas dissipates from the area.
Locate the appliance's pilot access panel per the owner's manual. Identify the pilot light as a small silver tube located near a copper thermocouple, which is attached to the appliance's thermostat control.
Use a wire brush to scrub the pilot tube vigorously. Use a file to scrape off built up debris. Then stick a toothpick down the pilot port to ensure that it is clean.
Use a short puff of air from a can of air or an air compressor to blow out any dust from the pilot.
Attempt to light the pilot light again per your user's manual. Remove the pilot by using an adjustable wrench or pliers to loosen the nuts that attach it to the appliance's thermostat if it does not light again.
Look at the inside of the pilot and the tip to see if it is badly corroded; if so, take the pilot light with you to the hardware store to purchase a new one. Continue cleaning the pilot tube with the wire brush if soot and debris appear to be the problem.
Replace the pilot light by putting it back into the appliance and affixing the nuts that hold it in contact with the thermostat. Ensure that the pilot flame will contact the thermocouple wire and the appliance's burner.
Light the pilot by turning the appliance's gas back on, turning the gas control knob to "Pilot" and pushing the electronic ignition or lighting it with a long match. Hold the gas control knob in the pilot position for 30 to 60 seconds before turning it to "On." Refer to your user's manual for instructions on lighting the pilot on your appliance.
Replace the access panel on your appliance.
Shut off the gas to the appliance by turning the gas control knob to be perpendicular to the gas line. Wait 10 to 15 minutes for gas fumes to dissipate before working on the appliance.
Remove the access panel to the appliance to gain access to the thermocouple. Look for the copper thermocouple wire near the silver pilot tube. Inspect the copper surface of the thermocouple for built-up soot or discolouration.
Use a wire brush to gently clean off any soot and debris. File any stuck-on debris with a metal nail file.
Turn the gas on the appliance and attempt to light the pilot again. Turn the gas control knob to "Pilot," and then push the electronic ignition or light the pilot with a match. See if the pilot stays on. Turn off the gas if the pilot goes out again, and disconnect the thermocouple from the thermostat and the pilot assembly.
Take the thermocouple and appliance model number with you to the hardware store to purchase a replacement.
Place the new thermocouple on the appliance by tightening the nuts that attach one end to the thermostat, the other to the pilot assembly.
Turn on the gas again. Relight the pilot light. Watch to ensure that the pilot light stays on. Then replace the access panel.
Before changing out or cleaning the pilot or thermocouple, ensure that breezy doorways or windows aren't causing the flame to blow out. Seal up doors and windows and light the pilot. These instructions are for standard gas appliances such as furnaces, ovens and water heaters. Each model is different, so it's important to consult your user's manual to make sure that the repairs are performed accurately.
Do not attempt to work on gas appliances if you are uncomfortable with the repair. Natural gas can cause fires and accidents, so ensure that you're comfortable repairing the appliance or contact a service technician.