Comfortmaker Furnace Pilot Light Troubleshooting and Maintenance

The pilot light on a Comfortmaker furnace is a small but critical component that ensures reliable heating. This article explains how pilot lights work, common reasons a Comfortmaker furnace pilot light won’t stay lit, step-by-step troubleshooting, safe relighting procedures, routine maintenance tips, and when to call a professional. Following these guidelines helps prevent cold nights, reduce repair costs, and maintain safe operation.

Issue	Likely Cause	Quick Fix
Pilot Won’t Light	Dirty pilot or gas supply issue	Clean or check gas valve
Pilot Lights Then Goes Out	Faulty thermocouple or draft	Inspect/replace thermocouple; seal drafts
Weak Yellow Pilot	Blocked orifice	Clean orifice; check gas pressure

How A Comfortmaker Furnace Pilot Light Works

The pilot light is a continuously burning flame used to ignite the main burners in older Comfortmaker gas furnaces. A thermocouple or thermopile senses the pilot flame and keeps the gas valve open; if the flame goes out, the sensor cools and closes the valve to prevent gas leaks. Understanding this safety circuit is key to safe troubleshooting.

Common Symptoms Related To Pilot Light Problems

Identifying symptoms guides efficient diagnosis. Common signs include: a pilot that refuses to light, a pilot that lights but extinguishes after a few seconds, a weak or yellow pilot flame instead of a steady blue flame, furnace failing to ignite the main burners, and a smell of gas near the unit.

Primary Causes Of Pilot Light Issues

Pilot light problems typically stem from mechanical, environmental, or maintenance-related issues. Frequent causes include a dirty pilot orifice, a failing thermocouple, gas supply interruptions, drafts that blow out the flame, or a malfunctioning gas control valve. Less common causes include improper gas pressure and internal furnace wiring faults.

Troubleshooting Steps For Comfortmaker Furnace Pilot Light

Safety First

Before any inspection, turn off the furnace power and shut the gas off at the appliance or main valve if there is a strong gas odor. If a significant gas leak is suspected, evacuate the home and call the gas utility or emergency services. Never attempt repairs beyond simple cleaning or relighting if unsure.

Step-By-Step Checks

1. Confirm Gas Supply: Verify the home’s gas supply is active. Check other gas appliances. If none function, contact the gas company.

2. Inspect Pilot Assembly: Remove the access panel to locate the pilot light and thermocouple. Look for soot, spider webs, or debris near the pilot orifice and pilot tube.

3. Check For Drafts: Drafts from vents, fans, or nearby doors can extinguish the pilot. Temporarily close adjacent doors and turn off exhaust fans to test if the pilot remains lit.

4. Observe Flame Quality: A healthy pilot flame is steady and blue with a small inner cone. A yellow or flickering flame suggests a clogged orifice or combustion air issue.

5. Test Thermocouple: With the pilot lit, gently hold the thermocouple tip in the flame. If the pilot stays lit only while someone holds the gas control knob, the thermocouple may be weak and require replacement.

6. Listen For Clicking Or Hissing: Hissing can indicate a gas leak; clacking or repeated attempts to light point to a faulty valve or ignition control.

How To Safely Relight A Comfortmaker Furnace Pilot Light

Only relight the pilot if there is no detectable gas smell. Follow the furnace manufacturer’s label instructions on the unit. The general procedure applies to many Comfortmaker pilot models but consult the owner’s manual for model-specific steps.

General Relighting Procedure

1. Turn Off The Gas: Rotate the gas control knob to OFF and wait five minutes to clear residual gas.

2. Set To Pilot: Turn the knob to the PILOT position and depress it while lighting with a long-reach lighter or match, or use the furnace’s built-in igniter if present.

3. Hold The Knob: Keep the knob depressed 20–30 seconds after lighting to allow the thermocouple to heat up.

4. Release And Test: Slowly release the knob. If the pilot stays lit, turn the control to ON and restore power to the furnace.

If relighting fails after several attempts, stop and proceed with further troubleshooting or call a professional.

Thermocouple And Thermopile: Roles And Replacement

The thermocouple is a safety sensor that generates a millivolt signal when heated by the pilot flame, keeping the gas valve open. Thermopiles produce higher voltage for standing pilot systems that power electronic controls. These components wear out over time and are a frequent cause of pilot failures.

Testing And Replacing

Testing usually requires a multimeter to measure voltage while the pilot is lit. A thermocouple typically produces around 25–30 millivolts; below that, replacement is recommended. Replacement is a straightforward mechanical job for someone comfortable with gas appliances, but hiring an HVAC technician ensures proper fit and safe reassembly.

Cleaning The Pilot Orifice And Burner

A blocked pilot orifice often causes weak or yellow flames. Cleaning requires a delicate approach: turn off gas and power, use compressed air or a fine needle to remove deposits, and avoid enlarging the orifice. Clean the nearby burner ports and the pilot tube to restore proper flow. Regular cleaning can prevent most pilot-related problems.

Gas Valve And Control Issues

The gas control valve regulates fuel to both pilot and main burners. If the pilot assembly and thermocouple test good, the valve may be internal-faulty. Signs include persistent refusal to supply gas despite a hot thermocouple or intermittent operation. Gas valve replacement should be performed by a licensed technician because it involves gas line work and pressure testing.

When Drafts And Venting Cause Pilot Problems

Indoor drafts or chimney venting issues can extinguish the pilot. Inspect vent connectors, flues, and combustion air openings for blockages, bird nests, or improper installation. Ensure exhaust vents are clear and that the furnace room has adequate combustion air. Sealing gaps and correcting vent slope can stabilize pilot performance.

Common Model-Specific Notes For Comfortmaker Furnaces

Comfortmaker has used both standing pilot systems and electronic ignition across models. Standing pilot systems rely on a constant pilot flame and thermocouple; newer models may use hot surface igniters or intermittent pilot systems that eliminate a continuous flame. Identifying the type simplifies troubleshooting: standing pilots require pilot maintenance, while electronic ignitions need electrical diagnostics.

Maintenance Schedule To Prevent Pilot Issues

• Annual Professional Inspection: Schedule an HVAC tune-up to check gas pressure, pilot assembly, thermocouple, and venting.

• DIY Visual Check Every 3–6 Months: Look for soot, insect nests, and debris near the burner and pilot area.

• Replace Thermocouple Every 3–5 Years: Consider proactive replacement in older systems or when intermittent problems begin.

• Keep Combustion Area Clean: Avoid storing flammable items near the furnace and seal gaps that create drafts.

Safety Tips And Warning Signs

Always prioritize safety. If the furnace has a persistent gas smell, a pilot that won’t stay lit despite correct procedure, repeated gas valve cycling, or visible damage to gas lines, stop attempting DIY fixes and call a licensed HVAC technician. CO detectors should be installed near sleeping areas and the furnace room as an added safeguard.

Cost Expectations For Repairs And Parts

Costs vary regionally and by the extent of repair. Typical ranges: thermocouple replacement $75–$200; pilot orifice cleaning $50–$150 if performed by a technician; gas valve replacement $300–$800 plus labor. A full furnace replacement is a larger expense considered when multiple major components fail or the system is aged.

When To Replace The Furnace Instead Of Repairing

Repair may not be cost-effective for furnaces older than 15–20 years, systems with repeated ignition-related failures, or units with inefficient operation and high repair frequency. Upgrading to a newer, energy-efficient Comfortmaker model or equivalent can reduce utility bills and eliminate standing pilot maintenance.

Finding Professional Help And Warranties

Use licensed HVAC contractors with gas appliance experience for pilot light and gas valve work. Verify credentials, insurance, and references. Check any remaining Comfortmaker warranty or parts coverage before paying for replacements. A professional can also perform combustion efficiency testing and carbon monoxide checks.

Key Takeaways And Practical Checklist

• Keep the pilot area clean and free of drafts; a clean, blue flame is ideal.

• Test or replace the thermocouple when the pilot lights then goes out.

• Relight only after confirming no gas odor and following manufacturer steps.

• Call a licensed technician for gas valve work, persistent problems, or safety concerns.

Checklist For Quick Field Use: confirm gas supply, inspect and clean pilot orifice, test thermocouple, check for drafts, and contact a pro if relighting fails.

For specific Comfortmaker model procedures and parts, consult the furnace manual or Comfortmaker’s official support resources. Regular maintenance and prompt attention to pilot issues keep a Comfortmaker furnace functioning safely and efficiently.