Without a lit pilot light, your furnace is unable to heat your house. If the light won't stay on, there could be a number of things causing the problem; here are common reasons why your furnace's pilot light won't remain lit so that you have a better idea of what's going on.
The Furnace Burners Need to Be Cleaned
One basic reason for a pilot light that won't stay on is that your furnace's burners are dirty. Mineral deposits, dirt, dust, and rust can occlude the burners, and that can make it difficult for the pilot light to burn effectively. You may be able to fix this problem by simply using an old toothbrush to scrub away debris. To do this, first shut off the gas supply and wait for the furnace to cool. Then briskly brush the burners until the debris is gone.
Something Is Wrong with the Sensors
Your furnace is equipped with sensors that serve to protect you and the appliance. If something is amiss with the furnace's sensory devices, the pilot light and the furnace may stop working properly. For example, the thermocouple, a device that typically kicks in once the pilot light is out, could be malfunctioning and therefore causing the situation it is meant to protect against. If that's the case, a simple replacement device can be installed. The sensor in the pilot light itself may shut off the light if it cannot determine that gas is flowing. That might need to be replaced as well.
There Is Low Gas Pressure
In some cases where there is a flickering or nonworking pilot light, the problem may not lie with the furnace itself. The culprit could be your gas supply. While the gas could be flowing, the pressure may be too low to sustain a strong light. This may happen if you're putting too high of a demand on your gas line; an example of this is if your furnace is running at the same time you are cooking a big meal on your gas stove.
However, low gas pressure could indicate that there is a leak somewhere in the gas line. If there is a strong gas odor and the pilot light is out, leave your home and place a call to your HVAC contractor immediately.
Now that you're better aware of the reasons for a faulty pilot light, you are one step closer to getting the situation resolved. Contact a local heating contractor such as Washam Plumbing Heating & Air Conditioning who can isolate the problem and assess the entire furnace so they can repair it for you.