Airtemp Furnace Pilot Light Troubleshooting and Repair

The pilot light on an Airtemp furnace is a small but critical component that ensures reliable heating. This article explains how the pilot light works, common problems, step-by-step relighting instructions, safety precautions, maintenance tips, and when professional service is required. The guidance is tailored for U.S. homeowners seeking practical HVAC help.

Issue	Possible Cause	Action
Pilot Won’t Stay Lit	Dirty pilot or thermocouple failure	Clean pilot or replace thermocouple
No Pilot Flame	Gas supply off or clogged orifice	Check gas valve; clean or replace orifice
Weak Flame	Low gas pressure or obstructed burner	Inspect line and burner; call pro for pressure issues

How The Airtemp Furnace Pilot Light Works

The pilot light is a continuously burning flame that ignites the main burners when the thermostat calls for heat. On many Airtemp furnaces the pilot assembly includes a pilot orifice, a flame-sensing thermocouple or thermopile, and a gas control valve. The thermocouple detects the flame and keeps the gas valve open; if the flame goes out, the thermocouple cools and the valve closes to prevent gas leakage.

Common Pilot Light Problems And Causes

Airtemp pilot light issues typically fall into a few predictable categories. Clogged pilot orifice from dust or spider webs reduces or extinguishes the flame. Faulty thermocouple or thermopile prevents the gas valve from staying open. Gas supply problems such as a closed gas valve, low line pressure, or a tripped gas meter can stop the pilot. Drafts, corrosion, or misadjusted pilot flames can also cause intermittent failures.

Safety Precautions Before Working On A Pilot Light

Prioritizing safety reduces risk. Always shut off the furnace at the main power switch and set the thermostat to off. Turn the gas control knob to the “off” position and wait five minutes to allow residual gas to clear. Avoid relighting if a strong odor of gas exists; instead, evacuate the area and call the gas utility or 911. Use only a long lighter or match to relight the pilot to keep hands away from the assembly.

Step-By-Step Relighting Procedure For An Airtemp Furnace Pilot

These are general steps applicable to many Airtemp models. Consult the furnace’s data plate and manual for model-specific instructions before starting. If the furnace uses an electronic ignition rather than a standing pilot, do not attempt this procedure.

1. Locate The Pilot Assembly: Open the furnace access panel to find the pilot assembly and gas control knob labeled “Pilot,” “On,” and “Off.”

2. Turn Gas Control To Off: Rotate the gas control knob to “Off” and wait at least five minutes to clear any gas odor.

3. Set To Pilot Position: Turn the gas control to the “Pilot” position and press and hold the control knob down to allow gas to flow to the pilot orifice.

4. Ignite The Pilot: While holding the knob, use a long lighter or match to ignite the pilot. Keep the knob depressed for 20–60 seconds to warm the thermocouple.

5. Release And Test: Release the knob. The pilot should remain lit. If it goes out immediately, repeat once more; if it still won’t stay lit, a thermocouple or gas valve issue is likely.

6. Return To “On”: If the pilot stays lit, turn the gas control to the “On” position and replace the access panel. Restore power and test furnace operation via the thermostat.

Troubleshooting Steps If Relighting Fails

If the pilot cannot be relit or doesn’t stay lit, follow these diagnostic steps. Begin with the easiest tasks and progress to parts replacement or professional help.

• Check Gas Supply: Verify the home’s gas supply is on, the service shutoff near the furnace is open, and other gas appliances are operating.

• Inspect For Drafts And Debris: Remove dust, spider webs, and other debris from around the pilot and burner using compressed air or a soft brush.

• Clean Pilot Orifice: A clogged orifice restricts fuel. Carefully remove and clean the pilot tube or orifice with compressed air or a fine wire, following manufacturer guidance.

• Test Thermocouple: Use a multimeter to check the thermocouple voltage while the pilot is lit; typical open-circuit voltage is between 20–30 mV for many units. A weak signal indicates a failing thermocouple or poor connection.

• Inspect Thermocouple Positioning: Ensure the thermocouple tip is correctly positioned in the pilot flame. Misalignment can keep the valve closed.

• Evaluate Gas Valve: A defective gas control valve may fail to deliver steady pilot gas. Valve replacement is a more advanced repair best handled by a licensed technician.

Replacing Common Parts: Thermocouple, Pilot Orifice, And Gas Valve

Thermocouples and pilot orifices are relatively inexpensive and often replaceable by a competent DIYer. Gas valve replacement is more complex and may require local licensing.

Part	Typical Cost Range (U.S.)	Skill Level
Thermocouple	$10–$50	Beginner–Intermediate
Pilot Orifice	$5–$25	Beginner
Gas Control Valve	$150–$500+	Advanced / Professional

When replacing the thermocouple, ensure a proper match for the Airtemp model and tighten the compression fitting securely without over-torquing. When in doubt, document the old part and consult the furnace manual or supplier to confirm compatibility.

Maintenance Tips To Keep The Pilot Light Reliable

Regular maintenance reduces pilot failures and extends furnace lifespan. Recommended maintenance includes annual inspections by an HVAC technician, cleaning the pilot assembly and burner, checking gas pressure, and verifying electrical connections. Replacing aging thermocouples proactively can prevent cold-weather failures. Keep the furnace area free of dust and stored items to prevent airflow or ignition interference.

When To Call A Professional

Professional service is recommended when troubleshooting points to gas pressure issues, a faulty gas valve, persistent pilot outages after cleaning and part replacement, or when the furnace uses electronic ignition. A licensed HVAC technician can perform safe gas valve replacement, adjust manifold pressure, and test system controls. Call a professional immediately if the smell of gas is present.

Signs The Pilot Problem Is Causing Bigger Issues

Pay attention to recurring pilot outages, yellow or flickering flames (which can indicate incomplete combustion), strange odors, soot buildup, or the furnace cycling frequently. These symptoms may suggest deeper problems like blocked flues, poor ventilation, or faulty control modules and warrant prompt professional diagnosis.

Model-Specific Notes For Airtemp Furnaces

Airtemp models vary in ignition type; many older units use standing pilots, while newer ones use electronic ignition systems that lack a constantly burning pilot. Refer to the furnace’s data plate and manual for the ignition type and part numbers. For older Airtemp standing-pilot furnaces, original equipment thermocouples and orifices often have specific fittings and lengths—using the correct OEM or equivalent part is important for reliable operation.

Cost Considerations And Warranties

DIY repairs such as cleaning or thermocouple replacement can be low cost, often under $100 including parts. Professional service for gas valve replacement or full tune-ups typically ranges from $150 to $600 depending on region and complexity. Check any existing warranties—furnace components may still be covered, especially on newer Airtemp systems, and manufacturer-authorized service may be required to preserve coverage.

Frequently Asked Questions

Why Does The Pilot Go Out After Relighting?

Immediate shutoff usually indicates a bad thermocouple, loose connection, or an incorrectly positioned thermocouple tip. Persistent outages after cleaning point to component failure or gas valve issues.

Can A Pilot Light Be Adjusted To Burn Hotter?

Pilot flames are set by orifice size and gas pressure. Attempting to increase flame without proper equipment can be dangerous. Adjustment of manifold pressure should be performed by a licensed technician.

Is It Safe To Leave The Pilot Off During Summer?

Yes. Turning the furnace gas control to “Off” during warm months prevents unnecessary gas use and reduces wear. Follow the manufacturer’s relighting procedure when restarting the furnace.

How Long Should A Thermocouple Last?

Thermocouples often last several years but can fail sooner due to corrosion, vibration, or flame contamination. Routine inspection during annual maintenance helps identify wear early.

Resources And Next Steps

For model-specific instructions, consult the Airtemp furnace manual or the manufacturer’s website. For gas odor or complex repairs, contact the local gas utility or a licensed HVAC contractor. Documenting model and serial numbers before calling for service speeds diagnostics and parts ordering.

Key Takeaway: Many Airtemp furnace pilot light problems are solvable with careful cleaning, correct relighting technique, and timely thermocouple replacement, but safety and gas-related repairs should involve a qualified professional.