Why Won't My Pilot Light Stay Lit?

A pilot light that won't stay lit usually points to a faulty thermocouple, dirty pilot opening, or draft issues in your home. Chicago homeowners face this problem often during harsh winters. The fix can be simple or require professional help.

Your furnace needs a steady pilot flame to heat your home safely. When it keeps going out, you waste money and risk cold nights. Understanding the cause helps you decide between a DIY fix and calling a pro.

In this blog, we will explain why your pilot light won't stay lit and how to fix it. You will learn to spot warning signs, troubleshoot common problems, and know when to call for help.

What a Furnace Pilot Light Is and How It Works

A pilot light is a small, continuous flame inside your gas furnace. It ignites the main burner when your thermostat calls for heat. This tiny flame burns natural gas 24/7 during heating season.

The pilot light works with a safety device called a thermocouple. This sensor detects heat from the pilot flame. When the flame burns properly, the thermocouple signals the gas valve to stay open.

If the pilot goes out, the thermocouple cools down within seconds. It then closes the gas valve automatically. This safety feature prevents dangerous gas leaks in your Chicago home.

Older furnaces built before the mid-1990s typically use standing pilot lights. These systems are reliable but less efficient than modern alternatives. They consume gas constantly, even when not actively heating.

Signs Your Pilot Light Is Not Working Correctly

Catching pilot light problems early saves you from cold nights and costly repairs. Watch for these warning signs in your furnace.

Pilot Flame Is Weak or Flickering

A healthy pilot flame burns steady and strong. Weak or flickering flames struggle to heat the thermocouple properly. This causes intermittent shutoffs that frustrate homeowners.

Flickering often indicates airflow problems near your furnace. It can also signal a partially clogged pilot opening. Either issue needs attention before complete failure occurs.

Pilot Flame Appears Yellow or Orange

A proper pilot flame burns bright blue with a small yellow tip. Yellow or orange flames indicate incomplete combustion. This color change signals a serious problem.

Orange flames mean your pilot isn't getting enough oxygen. Dirty components or ventilation issues cause this problem. Yellow flames can also produce carbon monoxide, making this a safety concern.

Pilot Light Will Not Ignite or Stay Lit

The most obvious sign is a pilot that won't light at all. You may hear gas hissing but see no flame. Or the flame lights briefly then dies.

This symptom points to thermocouple failure, gas supply issues, or severe contamination. Multiple failed attempts to relight warrant professional inspection. Don't keep trying if you smell gas strongly.

Common Reasons a Pilot Light Goes Out and How to Fix Them

Several issues cause pilot light failures in Chicago homes. Here are the most common culprits and their solutions.

Faulty or Dirty Thermocouple

The thermocouple is the most common cause of pilot light problems. This small sensor fails more often than any other furnace component.

Cause: Dirt, Corrosion, or Misalignment Prevents Proper Heating

Thermocouples get dirty from dust and combustion byproducts over time. Corrosion builds up on the sensor tip after years of use. Sometimes the thermocouple bends away from the pilot flame.

When dirty or misaligned, the thermocouple can't sense heat properly. It tells the gas valve to shut off even with a lit pilot. This creates the frustrating cycle of relighting your furnace repeatedly.

Solution: Clean, Replace, or Realign the Thermocouple

Start by gently cleaning the thermocouple tip with fine sandpaper. Remove any visible buildup or discoloration. Make sure the sensor sits directly in the pilot flame path.

Replacement thermocouples cost between $15 and $35 at hardware stores. Installation takes about 20 minutes for handy homeowners. If cleaning and realignment don't work, replacement usually solves the problem.

Dirty or Misaligned Pilot Opening

The pilot orifice is a tiny hole where gas exits to create the flame. This small opening clogs easily with dust and debris.

Cause: Clogged Opening Reduces Flame Strength

Dust, dirt, and spider webs accumulate in pilot openings over time. Even small obstructions reduce gas flow significantly. A restricted opening produces a weak flame that can't heat the thermocouple.

Chicago's dusty basements contribute to this problem. Homes near construction sites see faster buildup. Older furnaces with years of accumulated debris suffer most.

Solution: Clean and Realign the Pilot Opening for a Strong Blue Flame

Turn off gas to your furnace completely before cleaning. Use a thin needle or compressed air to clear the orifice. Be gentle to avoid enlarging or damaging the opening.

Check that the pilot tube points directly at the thermocouple. Misalignment prevents proper heating even with a clean opening. A strong blue flame should engulf the thermocouple tip when properly adjusted.

Insufficient Oxygen or Ventilation

Gas combustion requires adequate oxygen supply. Restricted airflow causes incomplete burning and pilot problems.

Cause: Restricted Airflow Disrupts Combustion

Furnaces need fresh air to burn gas efficiently. Blocked vents, sealed rooms, or cluttered utility areas restrict airflow. Modern weatherization sometimes creates overly tight spaces.

Insufficient oxygen produces weak, yellow flames. The pilot struggles to stay lit without proper combustion. This problem worsens in tightly sealed Chicago homes.

Solution: Improve Ventilation and Remove Obstructions

Clear the area around your furnace of stored items. Ensure combustion air vents aren't blocked by debris. Keep at least three feet of clearance on all sides.

Consider adding a fresh air intake if your home is very tight. A licensed HVAC technician can assess your ventilation needs. Proper airflow improves both safety and efficiency.

Indoor or Outdoor Drafts

Air currents blow out pilot lights more often than homeowners realize. Chicago's windy conditions make this especially common.

Cause: Air Currents Blow Out the Pilot Flame

Strong drafts near your furnace extinguish the small pilot flame. Leaky basement windows let cold air rush past the burner. Nearby doors or HVAC returns create problematic airflow.

Outdoor wind affects furnaces through flue pipes and fresh air intakes. Chicago's notorious winds penetrate older homes easily. Seasonal changes in wind direction cause intermittent problems.

Solution: Identify Draft Sources and Stabilize Airflow

Check for air leaks near your furnace location. Seal gaps around basement windows and doors. Install draft guards where needed.

Examine your furnace's draft hood for proper function. A damaged or missing hood allows backdrafts. Consider a wind-resistant flue cap if outdoor wind causes problems.

Gas Supply or Gas Valve Issues

Without adequate gas flow, your pilot can't stay lit. Supply problems range from simple to complex.

Cause: Low or Interrupted Gas Flow

Partially closed gas valves restrict fuel to the pilot. Kinked or damaged gas lines reduce flow. Faulty regulators fail to maintain proper pressure.

Gas supply interruptions from utility work cause sudden outages. Unpaid bills result in service disconnection. Multiple gas appliances running simultaneously can drop pressure.

Solution: Verify Gas Valve Position and Inspect Lines and Regulator

Check that all gas valves are fully open. The furnace valve, meter valve, and any inline valves must be on. Look for kinked flexible connectors near the furnace.

Verify other gas appliances work properly. If nothing works, contact your gas utility immediately. A licensed technician should inspect regulators and supply lines.

Low Gas Pressure in Older Chicago Homes

Chicago's aging infrastructure creates unique challenges for homeowners. Gas pressure problems affect many older neighborhoods.

Cause: Aging Gas Lines or Regulators Reduce Pilot Flame Stability

Older gas lines develop internal corrosion that restricts flow. Outdated regulators fail to maintain consistent pressure. Neighborhood-wide infrastructure issues affect entire blocks.

Many Chicago homes have original gas lines from decades past. These aging systems struggle during peak demand periods. Cold snaps stress the entire gas distribution network.

Solution: Inspect Gas Lines and Confirm Adequate Pressure

Contact your gas utility to check meter pressure. They test supply pressure at no charge. Low readings indicate infrastructure or regulator problems.

A licensed plumber can inspect interior gas lines. Corroded pipes may need replacement for safety. Upgrading old regulators often solves pressure inconsistencies.

How Chicago Climate and Housing Conditions Affect Pilot Lights

Chicago's unique environment creates specific challenges for furnace pilot lights. Understanding local factors helps you prevent problems.

How Extreme Winter Temperatures and Wind Drafts Impact Pilot Stability

Chicago winters regularly drop below zero degrees. Extreme cold increases heating demand dramatically. Your furnace works harder, and pilot lights face more stress.

The city's famous winds penetrate older homes easily. Lake-effect gusts create pressure changes that affect combustion. Pilot lights in exposed locations blow out during storms.

Temperature swings cause expansion and contraction in gas lines. This movement can loosen connections over time. Seasonal maintenance catches these issues before failures occur.

How Older Chicago Homes and Aging Gas Infrastructure Influence Furnace Reliability

Many Chicago homes date from the early 1900s. These buildings have original or outdated heating systems. Standing pilot furnaces remain common in older neighborhoods.

Aging gas infrastructure serves much of the city. Pressure fluctuations affect pilot light stability. Homes far from main gas lines experience more problems.

Older homes also have more air infiltration. Drafty basements and crawl spaces challenge pilot lights. Weatherization improvements help but can create ventilation issues.

How to Safely Relight a Furnace Pilot Light

Relighting a pilot light is straightforward when done safely. Follow these steps for older gas furnaces.

Step-by-Step Guide to Relighting Older Gas Furnaces

First, locate your furnace's gas control valve. It typically has three positions: On, Off, and Pilot. Turn the knob to Off and wait five minutes.

This waiting period lets any accumulated gas dissipate. Never skip this safety step. If you smell gas strongly after five minutes, leave immediately and call your utility.

Turn the knob to Pilot position. Press and hold the knob down firmly. This manually opens the gas valve to the pilot.

While holding the knob, light the pilot with a long match or lighter. Keep holding the knob for 30 to 60 seconds. This heats the thermocouple enough to keep gas flowing.

Release the knob slowly. The pilot should stay lit. Turn the knob to On position to resume normal operation.

Situations When You Should Not Attempt to Relight the Pilot Light

Stop immediately if you smell strong gas odors. Leave your home and call the gas company from outside. Gas leaks require professional response.

Don't relight if the pilot won't stay lit after three attempts. Repeated failures indicate a problem needing repair. Continuing wastes gas and risks safety.

Avoid relighting if you see damage to gas lines or connections. Cracked pipes, loose fittings, or corrosion require professional repair. Never use a furnace with visible damage.

If you feel uncomfortable or unsure, call a professional. There's no shame in prioritizing safety. Licensed technicians handle these situations daily.

Do Modern Furnaces in Chicago Still Use Pilot Lights

Furnace technology has evolved significantly over recent decades. Understanding your options helps with repair and replacement decisions.

Comparing Standing Pilot Furnaces and Electronic Ignition Systems

Standing pilot furnaces burn gas continuously to maintain the pilot flame. This design dates from the mid-20th century. Many Chicago homes still have these older systems.

Electronic ignition systems eliminate the standing pilot entirely. They ignite gas only when heat is needed. This design became standard in furnaces made after the mid-1990s.

Two main electronic ignition types exist today. Hot surface igniters use a glowing element to light gas. Intermittent pilot systems create a spark only during heating cycles.

How Electronic Ignition Systems Reduce Pilot Light Problems

Electronic ignition eliminates most pilot light issues entirely. No standing flame means no thermocouple failures. Draft problems become irrelevant without a continuous pilot.

These systems save money on gas bills too. Standing pilots consume $10 to $15 worth of gas monthly. Electronic ignition uses fuel only during active heating.

Modern furnaces also include advanced safety features. Flame sensors, pressure switches, and control boards monitor operation. Problems trigger automatic shutdowns before becoming dangerous.

If your standing pilot furnace needs major repairs, consider upgrading. New high-efficiency furnaces pay for themselves through energy savings. Chicago Comfort HVAC can help you evaluate your options.

Preventive Furnace Maintenance for Chicago Homeowners

Regular maintenance prevents most pilot light problems before they start. A simple annual routine keeps your furnace reliable.

Schedule professional maintenance before each heating season. Technicians clean burners, check gas pressure, and inspect safety controls. They catch small problems before cold weather arrives.

Between professional visits, change your furnace filter monthly. Dirty filters restrict airflow throughout your system. Clean filters improve efficiency and reduce strain on components.

Keep the area around your furnace clean and clear. Dust accumulation affects pilot lights and burners. Store nothing within three feet of your heating equipment.

Test your furnace before you need it desperately. Run the system in early fall to verify operation. Discovering problems in September beats freezing in January.

Watch for warning signs throughout heating season. Strange noises, unusual smells, or inconsistent heating indicate problems. Address issues promptly before complete failures occur.

When to Contact a Licensed HVAC Technician in Chicago, IL

Some pilot light problems require professional expertise. Knowing when to call saves time and ensures safety.

Contact a technician if your pilot won't stay lit after troubleshooting. Persistent problems indicate issues beyond basic maintenance. Professionals have tools and training to diagnose complex failures.

Call immediately if you smell gas that doesn't dissipate. Gas leaks are emergencies requiring professional response. Your utility company responds to leak reports 24/7.

Seek help for any visible damage to gas components. Cracked heat exchangers, damaged gas lines, or corroded fittings need expert repair. Never operate a furnace with known damage.

Consider professional help if your furnace is over 15 years old. Aging systems need more frequent attention. A technician can advise on repair versus replacement decisions.

Chicago Comfort HVAC provides expert furnace diagnosis and repair throughout Chicago. Our licensed technicians understand local conditions and older home challenges. We offer transparent pricing and honest recommendations for every situation.

Key Takeaways

• Thermocouple problems cause most pilot light failures in Chicago homes
• A proper pilot flame burns blue, not yellow or orange
• Chicago's wind and cold create unique challenges for standing pilot furnaces
• Wait five minutes before relighting to let gas dissipate safely
• Modern electronic ignition systems eliminate most pilot light issues
• Annual professional maintenance prevents most heating emergencies
• Call a licensed technician for persistent problems or gas smells

Conclusion

Pilot light problems frustrate Chicago homeowners every winter. Most issues trace back to dirty thermocouples, clogged openings, or draft problems. Understanding these causes helps you troubleshoot effectively.

Chicago Comfort HVAC helps homeowners solve furnace problems quickly and safely. We diagnose pilot light issues accurately and provide honest repair recommendations. Our technicians know Chicago's older homes and unique heating challenges.

We encourage you to schedule maintenance before winter arrives. Contact our team for expert furnace service throughout Chicago. Your comfort and safety are our top priorities.

FAQs

How much does it cost to fix a pilot light that won't stay lit?

Simple thermocouple replacement costs $100 to $200 including parts and labor. More complex repairs involving gas valves or controls run $200 to $400. Diagnostic fees typically range from $75 to $125.

Is it dangerous if my pilot light keeps going out?

A pilot that goes out isn't immediately dangerous due to thermocouple safety shutoffs. However, repeated relighting attempts can allow gas accumulation. Always wait five minutes between attempts and call a professional if problems persist.

How often should I have my furnace pilot light inspected?

Schedule professional furnace maintenance annually before heating season. Technicians inspect pilot assemblies, thermocouples, and gas connections during routine service. This prevents most pilot light problems before they occur.

Can I replace a thermocouple myself?

Yes, thermocouple replacement is a manageable DIY project for handy homeowners. Parts cost $15 to $35 at hardware stores. Turn off gas completely and follow manufacturer instructions carefully.

Why does my pilot light go out when it's windy outside?

Strong winds create pressure changes that affect furnace combustion. Drafts enter through flue pipes, fresh air intakes, or home air leaks. Installing wind-resistant flue caps and sealing air leaks usually solves this problem.

Should I upgrade from a standing pilot to electronic ignition?

Consider upgrading if your furnace needs major repairs or is over 20 years old. Electronic ignition systems eliminate pilot problems and save $120 to $180 annually on gas. New high-efficiency furnaces offer significant long-term savings.

How long should a thermocouple last?

Quality thermocouples typically last 8 to 12 years under normal conditions. Dirty environments or frequent cycling shorten lifespan. Replacement is inexpensive and straightforward when failure occurs.

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