Why Won’t My Furnace Pilot Light Stay Lit? A Troubleshooting Guide
During the cold winter months, a functioning furnace is crucial for maintaining a comfortable temperature in your home. If your furnace pilot light continuously goes out, it’s not only frustrating but can also be a safety issue. In this article, we’ll explore the various reasons why your furnace pilot light won’t stay lit and provide a step-by-step guide to help you troubleshoot and resolve the issue.
Why won’t my furnace pilot light stay lit?
Before we dive into the solution, let’s understand what causes a furnace pilot light to go out. Common reasons include:
• Dirty or clogged pilot air intake
• Incorrect fuel-air mixture
• Leaking gas lines
• Malfunctioning thermocouple
• Incorrect pilots orifice size
• Corrosion or clogged pilot orifice
Step 1: Check the Pilots Orifice Size**
The pilots orifice, also known as the **pilot jet**, allows a small amount of air to mix with the **pilot gas** during the ignition process. Insufficient air can cause the pilot light to go out. To check the orifice size:
* Loosen the orifice jet and clean it with compressed air or a soft cloth.
* Check the diameter of the orifice opening to ensure it’s clogged or restricted.
* Measure the orifice width and compare it to your furnace’s specifications.
**Table 1: Pilots Orifice Size Chart**
| Manufacturers | Pilots Orifice Size (inches) |
| — | — |
| Carrier |.012 -.015 |
| Trane |.012 -.018 |
| Lennox |.014 -.020 |
| American Standard |.014 -.018 |
| Rheem |.014 -.018 |
| Ruud |.012 -.015 |
| Amana |.014 -.018 |
| Goodman |.015 -.020 |
By ensuring the orifice opening is clean and the appropriate size for your furnace manufacturer, you can improve piloting performance.
Step 2: Check the Pilot Air Intake**
The pilot air intake is responsible for creating a draft that helps reignite the pilot light during each cycle. If dirty or clogged, airflow is restricted, causing the pilot light to go out. To check the intake:
* Remove any leaves, debris, or screen covers from the intake holes.
* Clean the ducts and vents with a soft brush or vacuum hose.
* Check for ducts or vents that have become disconnected or blocked due to insulation or other exterior factors.
Step 3: Regulate the Fuel-Air Mixture**
An inaccurate fuel-air mixture can significantly affect the pilot light stability. To adjust the ratio:
* Locate the access panel or screws covering the **pilot gas setting**.
* Use your furnace’s manual or supplier documentation to determine the desired ratio.
* Adjust the screw or setting to conform with recommended ratio specification (<40%/balance ≤|balance; 60%).For a more precise adjustment,
Step 4: Inspect Thermocouple and Gas Connection**}
A malfunctioning or dirty thermocouple is responsible for sensing the piloting temperature and providing temperature information to the furnace brain. Inspect the gas connection and thermocouple for:
* Leaking or corroded connections causing gas to escape.
* Dust, dirt, and rust buildup on the thermometer sensor.
* Thermocouple damage or broken signal wire.
Step 5: Power Cycle the Furnace System**
Sometimes, a short power cycle can resolve recurring pilots/light ignitors as
Conclusion **and Additional Tips**
Solving the issue of why your furnace pilot light stays lit requires a combination of thorough inspection, adjustment and troubleshooting. By following steps outlined in this article (Pilots Orifice Size, Pilot Air Intake, Fuel-Air Mixture, Thermocouple and Gas Connection*and Power Cycle), troubleshoot and resolve common culprit, you can maintain normal home to operate to an un.
