What to Do When Your Older Patch Home Furnace Pilot Light Keeps Going Out
\n\n
Your Patch home furnace pilot light keeps going out and you’re stuck in the cold. This is a common issue in St. Louis’s older neighborhoods where many homes still use standing pilot systems. Before you call for emergency repair let’s walk through the most likely causes and what you can safely check yourself. Emergency AC Repair in Creve Coeur That Won’t Break the Bank.
\n\n
The first thing to understand is that a pilot light that won’t stay lit often signals a safety problem. The thermocouple which senses whether the pilot flame is burning may be dirty or failing. Or you could have a clogged pilot orifice a draft issue in your basement or even a cracked heat exchanger that’s allowing dangerous carbon monoxide to build up.
\n\n
If you smell gas or your carbon monoxide detector is sounding leave the house immediately and call Spire Energy’s emergency line. Don’t try to fix anything yourself in those situations.
\n\n
5 Common Reasons a Pilot Light Won’t Stay Lit
\n\n
Understanding why your pilot light fails helps you decide whether it’s a quick fix or needs professional attention. Here are the five most common culprits in older Patch homes: Why Professional Air Duct Cleaning is Essential for Wildwood Homes.
\n\n
- \n
- Dirty or Broken Thermocouple
The thermocouple is a copper rod that sits in the pilot flame. When it gets coated with soot or corrosion it can’t generate the small electrical current needed to keep the gas valve open. You’ll notice the pilot lights but goes out as soon as you release the reset button.
- Clogged Pilot Orifice
Over time tiny particles can block the small opening where gas flows to the pilot. This creates a weak or irregular flame that won’t heat the thermocouple properly. The flame may look yellow instead of blue or it might flicker constantly.
- Strong Drafts in Basement or Crawl Space
Older Patch homes often have drafty basements where wind can blow out the pilot. Check if your furnace is near a window door or vent that might create a cross-breeze. The problem often worsens during St. Louis’s windy winter storms. The Best Local Furnace Replacement Options for Kirkwood Families.
- Improper Gas Pressure
If your home’s gas pressure is too low the pilot won’t get enough fuel to stay lit. This can happen if there’s a problem with the main gas line or if multiple gas appliances are running simultaneously. You might notice other gas appliances also performing poorly.
- Cracked Heat Exchanger
This is the most serious issue. A cracked heat exchanger can cause the pilot to go out and more importantly allows carbon monoxide to leak into your home. Signs include a yellow burner flame soot around the furnace or a rotten egg smell. This requires immediate professional attention.
\n
\n
\n
\n
\n
\n
\n\n
Troubleshooting Guide: DIY vs. Professional Repair
\n\n
Before you attempt any troubleshooting make sure you have a working carbon monoxide detector installed near your sleeping areas. If you’re unsure about any step call a licensed St. Louis HVAC technician instead.
\n\n
| Issue | DIY Safe? | What to Check | When to Call (314) 417-7771 |
|---|---|---|---|
| Dirty Thermocouple | Yes | Turn off gas remove thermocouple clean with fine sandpaper | If cleaning doesn’t work or you’re uncomfortable |
| Clogged Orifice | Limited | Visual inspection only don’t insert objects into orifice | Always call for cleaning |
| Draft Issues | Yes | Check for open windows seal gaps around furnace area | If drafts persist after sealing |
| Gas Pressure | No | Requires gas line testing equipment | Immediately for pressure issues |
| Heat Exchanger | No | Visual signs only requires disassembly to confirm | Immediately if you suspect cracks |
\n\n
Step-by-Step: How to Safely Relight Your Pilot Light
\n\n
If you’ve determined it’s safe to proceed here’s how to relight a standard standing pilot furnace. This applies to most older models found in Patch neighborhood homes built before 2000.
\n\n
- \n
- Locate the Gas Valve and Pilot Assembly
Find the gas control valve on your furnace. It will have three positions: Off Pilot and On. The pilot light assembly is usually near the bottom of the unit often behind a small metal cover.
- Turn Gas to Off Position
Rotate the valve to Off and wait at least five minutes. This allows any accumulated gas to dissipate. Never skip this step—it’s a critical safety measure.
- Set to Pilot Position
Turn the valve to the Pilot position. You’ll feel a slight resistance when it’s in the correct spot. Some valves have a red reset button you’ll need to hold down.
- Light the Pilot
While holding down the reset button bring a long lighter or match to the pilot opening. You should hear a faint hissing sound as gas flows. Once the pilot lights continue holding the button for 30-60 seconds.
- Release and Test
Slowly release the reset button. The pilot should stay lit. If it goes out immediately the thermocouple likely needs cleaning or replacement.
- Turn to On Position
If the pilot stays lit turn the gas valve to the On position. You should hear the main burners ignite when your thermostat calls for heat.
\n
\n
\n
\n
\n
\n
\n
\n\n
When to Call a St. Louis HVAC Expert
\n\n
Some pilot light problems require professional diagnosis and repair. Here’s when to pick up the phone and call (314) 417-7771 for emergency service:
\n\n
If your pilot light won’t stay lit after cleaning the thermocouple you’re likely dealing with a failing part that needs replacement. Modern thermocouples cost around $20-30 but installation requires shutting off gas and proper testing. Top Rated AC Installation Companies Serving Ladue and Clayton.
\n\n
Gas pressure issues need specialized equipment to diagnose. Low pressure can indicate problems with your home’s gas supply line or the main meter. This isn’t just about the pilot light—it affects all your gas appliances and can be dangerous.
\n\n
Heat exchanger cracks are serious business. The St. Louis County Mechanical Code Section 425.1 requires immediate shutdown of any furnace with a confirmed heat exchanger failure due to carbon monoxide risks. You can’t see these cracks with the naked eye—they require a combustion analyzer test.
\n\n
Older Patch homes built between 1940-1970 often have galvanized steel gas lines that corrode from the inside out. If your home is in this age range and you’re experiencing recurring pilot issues the problem might be in the gas supply rather than the furnace itself.
\n\n
St. Louis’s freeze-thaw cycles put extra stress on older gas lines. When ground shifts during winter it can affect gas pressure to individual homes. This is especially common in areas near the Missouri River where soil composition changes seasonally.
\n\n
Don’t wait until your house is freezing to call for help. Keystone HVAC offers 24/7 emergency service throughout St. Louis County including the Patch neighborhood with technicians who understand the specific challenges of older St. Louis homes.
\n\n
Preventing Future Pilot Light Problems
\n\n
Annual furnace maintenance can prevent most pilot light failures. During a tune-up technicians clean the thermocouple and pilot assembly check gas pressure inspect the heat exchanger and test for carbon monoxide leaks.
\n\n
The EPA recommends replacing furnaces over 15 years old especially those with standing pilots. Modern furnaces use electronic ignition systems that eliminate many of these problems and are significantly more energy-efficient. Air Purification Systems.
\n\n
If you live in a drafty Patch home consider adding insulation around your furnace area or installing a wind guard. Simple foam weather stripping around basement windows can make a surprising difference in pilot light stability.
\n\n
Keep the area around your furnace clean and free of clutter. Don’t store chemicals paint or other volatile substances near gas appliances. These can interfere with proper combustion and create safety hazards.
\n\n
Install a carbon monoxide detector if you don’t have one. In Missouri the law requires CO detectors within 10 feet of every sleeping area in homes with fuel-burning appliances. Test your detector monthly and replace batteries annually.
\n\n
Consider upgrading to a high-efficiency furnace with a sealed combustion system. These units draw combustion air from outside rather than your basement eliminating draft issues entirely. While the upfront cost is higher you’ll save on energy bills and avoid these recurring problems.. Read more about Is Leasing a New HVAC System Actually a Good Deal for St. Louis Homeowners?.
\n\n
Frequently Asked Questions
\n\n
Why does my pilot light keep going out even after I relight it?
\n
The most common cause is a dirty or failing thermocouple that can’t generate enough electrical current to keep the gas valve open. Other possibilities include a clogged pilot orifice drafts in your basement or low gas pressure. If cleaning the thermocouple doesn’t solve the problem you need professional diagnosis.
\n\n
Is it dangerous if my pilot light keeps going out?
\n
It can be. While a pilot light going out isn’t immediately dangerous it often indicates underlying problems like a cracked heat exchanger that could leak carbon monoxide. Always have working CO detectors installed and if you smell gas or your detectors alarm leave immediately and call for emergency service.
\n\n
How much does it cost to fix a pilot light that won’t stay lit?
\n
Costs vary widely depending on the cause. A simple thermocouple cleaning might cost $75-150 while replacing a thermocouple runs $150-250. More serious issues like gas line problems or heat exchanger replacement can cost $500-2000 or more. We provide upfront pricing before any work begins.
\n\n
Can I just keep relighting the pilot light myself?
\n
You can for a short period but repeatedly relighting a failing system isn’t safe or economical. Each time the pilot goes out you’re experiencing incomplete combustion and potential gas waste. More importantly you’re ignoring a symptom of a potentially dangerous problem that needs professional attention.
\n\n
How long should a furnace pilot light stay on once lit?
\n
A properly functioning pilot light should stay on continuously as long as the gas valve is in the On position. If it goes out within minutes or hours of lighting something is wrong. In standing pilot systems the flame should be steady and blue not flickering or yellow.
\n\n
Local Patch Neighborhood Considerations
\n\n
The Patch neighborhood located near the intersection of Interstate 55 and South Broadway has many homes built in the 1920s-1940s era. These properties often feature original gravity furnaces or early forced-air systems with standing pilot lights. The area’s proximity to the Mississippi River means higher humidity levels that can accelerate corrosion on furnace components.
\n\n
Many Patch homes have basements with fieldstone foundations that shift slightly over time. This settling can create small gaps that allow drafts to reach your furnace area. During St. Louis’s windy winter months these drafts become more pronounced and can easily blow out pilot lights.
\n\n
The neighborhood’s mature tree canopy while beautiful can also contribute to the problem. Falling leaves and debris can clog exterior vents causing negative pressure in basements that draws air through furnace areas and extinguishes pilot lights.
\n\n
If your Patch home was built before 1970 it likely has a natural draft furnace that relies on proper venting to function safely. These older systems are particularly sensitive to even minor draft issues that newer sealed-combustion furnaces would ignore.
\n\n
Call (314) 417-7771 today to schedule your inspection. Don’t wait until your house is freezing to address pilot light problems. Our technicians understand the specific challenges of Patch neighborhood homes and can get your heat working safely and reliably.
\n\n
Pick up the phone and call (314) 417-7771 before the next storm hits. We offer same-day service throughout St. Louis County and can diagnose your pilot light issue quickly so you’re not left in the cold.
“,
“externalLinks”: [
{
“url”: “https://www.epa.gov”,
“anchorText”: “EPA recommendations”,
“reason”: “Source for furnace replacement guidelines”
},
{
“url”: “https://www.spireenergy.com”,
“anchorText”: “Spire Energy emergency line”,
“reason”: “Local gas utility emergency contact”
}
],
{
“suggestedImagePrompts”: [
“Close-up photo of a dirty furnace thermocouple showing soot buildup and corrosion”,
“Technician using a combustion analyzer to test a furnace heat exchanger for cracks”,
“Drafty basement window with foam weather stripping showing gaps that affect furnace operation”
]
}
“`
{
“@context”: “https://schema.org”,
“@type”: “BlogPosting”,
“headline”: “What to Do When Your Older Patch Home Furnace Pilot Light Keeps Going Out”,
“description”: “”,
“wordCount”: 2071,
“datePublished”: “2026-05-06T11:57:00.000Z”,
“dateModified”: “2026-05-06T11:57:00.000Z”,
“inLanguage”: “en-US”,
“mainEntityOfPage”: {
“@type”: “WebPage”,
“@id”: “https://keystonehvacstlouis.com”
},
“publisher”: {
“@type”: “LocalBusiness”,
“name”: “Keystone HVAC St. Louis”,
“url”: “https://keystonehvacstlouis.com”
},
“author”: {
“@type”: “Organization”,
“name”: “Keystone HVAC St. Louis”,
“url”: “https://keystonehvacstlouis.com”
},
“image”: {
“@type”: “ImageObject”,
“url”: “https://keystonehvacstlouis.com/wp-content/uploads/2026/03/what-to-do-when-your-older-patch-home-furnace-pilo-1.png”
}
}
{
“@context”: “https://schema.org”,
“@type”: “HVACBusiness”,
“name”: “Keystone HVAC St. Louis”,
“url”: “https://keystonehvacstlouis.com”,
“address”: {
“@type”: “PostalAddress”,
“addressLocality”: “St. Louis”
},
“areaServed”: {
“@type”: “City”,
“name”: “St. Louis”
}
}
{
“@context”: “https://schema.org”,
“@type”: “BreadcrumbList”,
“itemListElement”: [
{
“@type”: “ListItem”,
“position”: 1,
“name”: “Home”,
“item”: “https://keystonehvacstlouis.com”
},
{
“@type”: “ListItem”,
“position”: 2,
“name”: “Blog”,
“item”: “https://keystonehvacstlouis.com/blog”
},
{
“@type”: “ListItem”,
“position”: 3,
“name”: “What to Do When Your Older Patch Home Furnace Pilot Light Keeps Going Out”
}
]
}
{
“@context”: “https://schema.org”,
“@type”: “Service”,
“serviceType”: “HVAC”,
“provider”: {
“@type”: “LocalBusiness”,
“name”: “Keystone HVAC St. Louis”,
“url”: “https://keystonehvacstlouis.com”
},
“areaServed”: {
“@type”: “City”,
“name”: “St. Louis”
},
“description”: “”
}