In this article we will cover top 15 reasons why your gas furnace has stopped working and some of the most common causes of your furnace failure. If you have any questions, please do not hesitate to call us at (718) 509-5848 and speak with one of our HVAC experts.
Gas Furnace: The most common type uses natural gas or propane to heat an indoor air duct system. Fuel is ignited with pilot light and burns continuously until the thermostat calls for it to shut off.
The air return grille of the furnace has a heat sensor that is used to control the furnace cycling. So if the airflow is restricted, it may need to be cleaned or replaced.
Here are some problems and their causes:
- Air Filter Dirty: If your filter is dirty, this will restrict airflow into the furnace, and it will not produce any heat. Replace the dirty filter with a clean, fresh one.
- Capacitors: After a furnace has been on for several minutes, it may stop working or go into a lockout state which is caused by faulty capacitors and may require repair or replacement depending on their age and build quality. Please call (718) 509-5848 to speak with one of our trained HVAC technicians, and they can help you troubleshoot and repair your furnace.
- Gas Valve: Over time, these valves wear out, get stuck, or leak. The valve is a very common problem in gas furnaces. If the gas valve isn't working properly, the furnace will not be able to ignite.
- Thermostat: Furnace thermostats wear out over time due to their age, wiring issues, or just poor design. Thermostats are a significant cause of furnace failure. If you have to replace your thermostat, consider upgrading to an electronic one.
- Blower Wheel: The blower wheel is the fan in your furnace that circulates air through the indoor air duct system. This wheel wears out over time and needs to be replaced periodically as long as it is not the cause of your problem.
- Forced Air Furnace: The forced air furnace has a blower fan that moves air through an indoor air duct system and heats it with either electric coils wrapped around a gas flame or burners on top of the furnace. These furnaces have several safety systems to prevent gas leaks, fire hazards, and overheating of electrical components. The gas safety valve will shut off the gas supply to the furnace if there is a pressure leak or problem.
- Burners: Electric furnaces usually have only one blower fan in the back of the furnace. If this is noisy or louder than usual, it may indicate a problem with your burners.
- Burner Igniter: The burner igniter is on top of some older electric furnaces, and it lights up the burners. If this isn't working, the burners won't ignite.
- Burner Coil: The burner coil is often found in forced air furnaces that use coils to heat an indoor air duct system. If the coils are not heating up or have failed, there will be no way for the furnace to produce any heat from a flame.
- Valve Coil: Some older furnaces use a valve coil to direct gas to either the burners or the blower fan in your furnace. If this is malfunctioning (leaking, stuck, won't shut off), you will not be able to receive any gas to that part of your furnace. Please call (718) 509-5848 to speak with one of our trained HVAC contractors, and they can help you troubleshoot and repair your furnace.
- Gas Safety Valve: The gas safety valve will shut off the gas supply to the furnace if there is a pressure leak or problem. It's common for this valve to fail and need to be replaced periodically as long as it is not the cause of your problem.
- Blower Assembly: In some furnaces, the blower is a separate part from the furnace. If this is noisy or louder than normal, it may indicate a problem with your blower assembly.
- Thermocouples: These devices allow furnaces to sense the heat in an air duct system or burner chamber and adjust accordingly so that there isn't any overheating of electrical components or underheating of a room. If these fail, the furnace may think the duct is hot when it isn't or vice versa. In some cases, it will shut down entirely and not work at all.
- Pilot Lights: Older style furnaces used pilot lights to ignite burners in electric furnaces or gas pilots for old glass tube style gas furnaces. If the pilot light isn't working, no heat can be produced in the furnace, or it will just shut down completely to prevent a fire hazard.
- Ignition Module: Some furnaces have an ignition module to ignite the burners and/or blower fan in gas furnaces or coils in forced air systems. If this is shutting off, your furnace will shut down due to overheating, or it won't start at all.
We hope that we have covered most of the important points this article that helps you solve your problem. If you need any help with you gas furnace repair please contact us at (718) 509-5848.