Why Your Pilot Light Keeps Going Out
September 29, 2026
Learn what can extinguish a pilot light, when one relight is reasonable and which warning signs mean you should evacuate.
Why Pilot Light Keeps Going Out: A Safety Warning
Your furnace, boiler or water heater pilot lights, then dies again. We’ll explain why your pilot light keeps going out, which mechanical and Niagara winter venting problems may be responsible, and when another relight is unsafe. You’ll also learn what you can check without opening the appliance and what a certified gas fitter should inspect. If you smell gas, hear hissing or have a carbon monoxide alarm, skip troubleshooting and follow the emergency steps below.
Top Mechanical Reasons Your Pilot Light Won’t Stay Lit
A failing thermocouple or thermopile is one of the most common causes. This safety sensor sits in the pilot flame and generates a small electrical signal that holds the gas valve open. If the sensor is worn, poorly positioned or no longer producing enough millivoltage, the valve closes and the pilot goes out. That shutdown is a safety feature, not something to bypass.
The flame itself may also be the problem. Dust, soot, oxidation or insect debris can restrict the pilot orifice and produce a weak or uneven flame. HVAC School’s thermocouple testing guidance explains that flame quality and the flame’s position on the thermocouple directly affect sensor operation.
Other possible faults include a damaged pilot tube, loose sensor connection or defective internal gas-valve coil. A flame that is small, unstable or mostly yellow needs professional attention. Do not take apart the burner, valve or combustion chamber to clean or test these parts yourself.
Niagara Drafts, Snowdrifts and Flue Backdrafts
Niagara winter weather can expose venting problems that remain unnoticed in milder conditions. Strong wind may create a downdraft at a chimney or vent termination, while heavy snow can obstruct an exterior intake or exhaust. Either condition can disrupt combustion air or push exhaust towards the burner, extinguishing the pilot.
Pressure inside your home matters too. A powerful range hood, clothes dryer or bathroom fan removes indoor air. In a tightly closed house without enough replacement air, that pressure difference can pull air backwards through an appliance flue.
From ground level, look for snow or loose debris around accessible exterior vent openings. Keep the area clear without removing components, climbing onto the roof or reaching into a pipe. If the pilot fails mainly during high winds, while exhaust fans run or after snowfall, leave the appliance off and arrange a venting inspection.
Safe Relighting Rules: The Two-Attempt Limit
Relight a pilot only when the appliance label or owner’s manual provides instructions and there is no gas smell, hissing, soot, visible damage or carbon monoxide alarm. Controls differ, so the appliance instructions take priority over general advice.
- Turn the appliance control to “Off.” Wait at least five to ten minutes so unburned gas can disperse. A large boiler or enclosed chamber may require the longer period stated by its manufacturer.
- Follow the label to select “Pilot.” Use only the built-in igniter or lighting method specified by the manufacturer.
- After ignition, keep the pilot control depressed for the stated period, commonly 30 to 60 seconds, then release it slowly.
- If the flame remains stable, return the control to its normal operating position. Watch from a safe distance for abnormal flame, soot or delayed ignition.
- If the first attempt fails, make no more than one additional attempt. If either attempt produces a flare, bang or delayed ignition, stop immediately.
Repeated attempts can introduce more unburned fuel into the combustion chamber. Hotwater.com warns that accumulated gas can ignite suddenly. Never hold a gas valve open, bypass a safety sensor or use an improvised flame source.
Critical Safety Warnings: Gas Smells and Carbon Monoxide Risks
A rotten-egg or sulfur smell indicates the odourant added to natural gas or propane. Audible hissing can also signal a pressurized leak. Do not relight the pilot or touch the appliance controls.
- Get everyone outside immediately, including pets.
- Do not operate lights, plugs, phones, garage-door controls or other electrical equipment while inside.
- From a safe outdoor location, call 911 and your gas utility’s emergency number.
- Stay outside until the utility or emergency responders say re-entry is safe.
Carbon monoxide is different because it has no smell. If a CO alarm sounds, or anyone has a headache, dizziness, nausea, confusion or unusual weakness, move outside and seek emergency help.
Soot around the burner, repeated flame rollout or unusual combustion sounds can point to incomplete combustion. Keep the equipment off until it has been inspected. Opening a window does not make relighting safe.
What a Certified Gas Fitter Checks
Professional service is needed when a pilot will not remain lit after the permitted attempts. Gas appliances must be inspected and repaired in line with safety standards, manufacturer requirements and local regulations. Thermal Comfort Solutions brings over 10 years of industry experience to certified gas-fitting services across Niagara.
During diagnosis, we may inspect the pilot flame and its alignment with the thermocouple or thermopile. Electrical testing shows whether the sensor maintains the required millivolt signal under load. We also check the pilot tube and orifice for restrictions and assess the gas valve’s safety coil for reliable shut-off.
A complete assessment can include checking inlet and manifold gas pressure against the appliance specifications, examining the vent and draft, and looking for burner damage or soot. If delayed ignition has occurred, the heat exchanger and nearby wiring may also need inspection. A cracked heat exchanger can allow combustion gases into the living space and requires the equipment to be shut down.
Routine preventative tune-ups can identify weak sensors, dirty pilot components and venting concerns before they cause a loss of heat during a Niagara cold spell.
Repairing vs. Replacing Aging Gas Equipment
Age changes the repair decision. According to Hotwater.com, conventional gas water heaters commonly last 8 to 12 years, furnaces 15 to 20 years and cast-iron boilers 15 to 30 years. Condition and maintenance history still matter, so age alone does not settle the question.
We recommend considering replacement when pilot failures keep returning, key gas-valve parts are obsolete or the appliance has a damaged heat exchanger. Repair may remain sensible when the equipment is otherwise sound and the fault is limited to a serviceable sensor, blocked pilot or misaligned flame.
Ask what caused the failure, what condition the rest of the appliance is in and whether replacement parts remain available. Compare the quoted repair with replacement cost and expected remaining service life rather than paying for repeated short-term fixes.
Book a Pilot Light Safety Inspection
If your pilot keeps going out, leave the appliance off and call Thermal Comfort Solutions at 289-696-4440 or email Thermalcomfortsol@gmail.com. You can request certified heating service and a free, no-obligation quote, or visit us at 2919 June Rd, Port Colborne, ON, Canada.
