A furnace pilot light being out means house and home are out of heat too. The pilot light is that small, continuously burning gas flame that ignites the furnaces’s main gas burner. Most furnaces manufactured in recent years don’t utilize a pilot light. Instead, an electronic igniter does the job.
However, many older furnaces that incorporate a pilot light are still in use. If you find the furnace pilot light out, the furnace automatically shuts down and will not respond to the thermostat.
What Can You Do Yourself?
There’s one do-it-yourself option you might try if you find the furnace pilot light out. Most furnaces include a procedure to relight the pilot. Instructions are typically printed on the furnace itself in some conspicuous spot, and they’re easy to follow. If the pilot won’t relight — or if the flame soon goes out again — contact your HVAC contractor to be put in touch with a qualified heating specialist.
Why Is the Furnace Pilot Light Out?
A furnace pilot light typically goes out for one of two reasons:
- Thermocouple issues. The thermocouple is a small but important safety device that senses heat produced by the pilot light. If the pilot flame goes out, the thermocouple stops the flow of gas to the main gas burner and the pilot. The furnace will not start up again until the pilot is relighted. Thermocouples typically have a limited life span. When an old thermocouple begins to fail, it may shut off gas randomly for no reason. In that case, the services of a qualified HVAC technician are required to troubleshoot the issue and replace the thermocouple with a new unit.
- An inefficient pilot flame. A properly functioning pilot light flame should be bright blue. However, if the pilot flame appears yellow and/or is flickering, this typically indicates a problem with flame efficiency. Often, the thermocouple will detect the lower temperature of an inefficient flame and automatically shut off gas flow to the pilot and the furnace. Restoring furnace heat requires diagnosis and repair of an inefficient pilot flame by a professional heating contractor.