Have you ever felt a cold chill that sends shivers down your spine in the middle of the night? Have you ever woken up in the middle of the night when it’s so cold that you can see your breath? Something is wrong. Your furnace stopped working at some point during the night causing the temperature in your home to fluctuate.
Your first instinct in this situation should be to inspect your furnace. If you notice that the pilot light is off, you should try to re-light it. The pilot light stays on for a moment and the furnace attempts to fire, but immediately shuts down. Why does this happen?
This furnace troubleshooting guide will explain the most common reasons why your furnace pilot light won’t stay lit and will help you decide whether it’s time for furnace replacement.
Age & Condition of Heating System
Most modern furnaces are lit with electronic ignition, so, if your furnace has a standing pilot light there is a good chance that it is 10-15 years old. An old heating system is likely to have many parts or components that have become warn, dirty, and inefficient throughout its lifespan. Any combination of failing parts can cause the pilot light to go out
The thermocouple on your furnace is the copper rod that the pilot flame makes direct contact with and determines whether or not the pilot light is lit. The thermocouple is positioned close to the flame, and when lit, the pilot light alerts the thermocouple to keep the gas line open. A dirty or malfunctioning thermocouple will shut off the furnace gas supply as it senses an error. This will in-turn cause the pilot light to go off and the furnace to stop working.
Improper Ventilation & Air Flow
In some cases, a pilot light can go out as a result of wind or airflow simply blowing it out. This can be caused by a draft during excessive windstorms. If this happens, there could be an issue with the ventilation of your system or a problem with how your flue pipe is set up.
Cracked Heat Exchanger
A cracked heat exchanger is an issue that is common among older systems and will cause your pilot light to go out. A crack in your heat exchanger will have a negative effect on the air pressure and ventilation in the combustion chamber of your furnace. Depending on the location or severity of the crack, air can be blown into the heat exchanger onto the flame causing it to go out.
Gas Valve and Gas Supply Issues
The pilot light of a furnace depends on a reliable fuel source in order to stay lit. Any problems associated with the gas valve that supplies fuel to the flame, whether it be dirty or functioning improperly, can result in the flame going out. Additionally, it is possible that the gas or fuel supply has run low altogether which will again cause the flame to blow out.
Is It Safe to Re-Light Your Pilot Light?
No matter what is causing your pilot light to go out, many homeowners have the question of whether it is safe to re-light the pilot on their own. Although in some instances it may be okay to re-light the pilot yourself, it is best to consult a trained HVAC specialist when dealing with furnace-related issues. Contact Certified Heating and Air Conditioning today with any issues related to your furnace or pilot light. One of our trained professionals is always happy to help!