There are several reasons why your furnace might stop working effectively. It can be difficult to troubleshoot and diagnose the problem without professional help. However, you can take some simple steps to ensure that your furnace is in good working order before calling for assistance.

1. Check the Thermostat

The thermostat is responsible for controlling the temperature in your home. If it isn’t working properly, this could be a major reason your furnace is not functioning as intended. Check to ensure that the thermostat is set correctly; if not, adjust the desired temperature, and see if that solves the issue.

Additionally, check any batteries within the thermostat (if applicable) to ensure they are still operational. You should also check that the thermostat is set to “Heat” or “On.” If it is set to “Off,” then your furnace will not be able to work properly. When it’s set to “On,” you can know that the thermostat is not the source of your furnace’s problems.

2. Examine Your Air Filter

An air filter keeps dirt and debris from entering your furnace and clogging its components. After a while, this filter can become clogged with dust or dirt, which can cause your furnace to malfunction. You should replace or clean your air filter every one to three months for optimal performance.

To check on your air filter, locate the filter, and examine it visually. If it appears dirty or clogged, you should replace it immediately to ensure that your furnace can work properly. At Honest Air Conditioning, we offer high-quality maintenance services, including air filter replacement, for Greenfield residents and the surrounding areas. Call us today to schedule an appointment.

3. Check Your Pilot Light

The pilot light is responsible for igniting the gas within your furnace and burning it as needed to heat your home. If this light is not burning correctly or has gone out, then this could be a sign of a larger problem with your furnace’s system. You should inspect this area carefully to ensure that everything looks normal and that there are no other issues present that may be causing the pilot light to go out or fail to ignite in the first place.

If the pilot light is no longer lit, you should carefully re-light it according to the manufacturer’s instructions. If this does not help or if the issue recurs, then it is best to call an HVAC technician for assistance in diagnosing and resolving any other problems with your furnace.

4. Your Blower Assembly

Your furnace’s blower assembly helps to circulate heated air throughout the home. If this part is not working properly, it can cause your furnace to run inefficiently or stop running altogether. You should check the blower regularly to ensure that all components are in proper working order and that there are no signs of damage or wear and tear.
If applicable, you should also inspect the fan belt to ensure it is in good condition and not worn out. If you find the blower assembly is not working as intended, it may be time to call an HVAC technician for assistance.

5. Check Your Fuel Source

Your furnace needs a steady supply of fuel to work properly. If the fuel source is low or has been cut off for any reason, then your furnace will not be able to operate as intended. You do as much as possible to ensure it is in good working order and at sufficient levels for your furnace to continue running without interruption.

Otherwise, if your fuel source may have an issue like a leak or other damage, an HVAC professional would be best placed to assess and address the situation and help get your furnace back up and running.

6. Exhaust Pipe

The furnace’s exhaust pipe is responsible for helping to filter out any dangerous fumes that the system may produce. If this pipe becomes blocked or damaged, your furnace could malfunction.

To avoid such an event, it is important to have maintenance on your exhaust pipe and inspect it for any signs of blockage or damage. If you find a blocked pipe, you should contact a technician to fix the problem to ensure the safety of your home.

7. Electrical Components

These components regulate the system’s performance and keep it running as needed. If any of these components become damaged or wear out, then your furnace won’t function properly. To ensure everything is in order, inspect all relevant wiring and connections for any signs of damage or fraying.

You should also check if the circuit breaker has tripped, which can signify an electrical issue. If you find any problems, it is best to call a technician to repair them and ensure that your furnace operates safely.

8. Flame Sensor

The role of a flame sensor is to detect when the fuel is burning correctly and prevent your furnace’s system from overheating. If this sensor becomes damaged or dirty, it may fail to detect the flame and cause your furnace to shut down unexpectedly. To check if this is causing an issue, you should inspect the sensor for any signs of dirt or damage.

You can either replace or clean this sensor if necessary. However, it is best to contact an HVAC technician if you need help with how to proceed. With the help of a professional, you can revive your furnace in no time.

9. Vents

When your furnace is running, it must release its air regularly. Blocked or closed vents will not allow your furnace to do this and can cause the system to overheat and shut down unexpectedly. To avoid such an event, you should ensure that all home vents are clear of any obstructions or blockages.

If you cannot locate a blockage in any vents, it may be time to call a professional for assistance. A technician can help identify any other issues causing the problem and get your furnace back up.

10. Ignitor

The ignitor is an electrical component that helps start your furnace’s combustion process. If this component becomes faulty, your furnace will not be able to start up, and you may experience frequent shutdowns.

To know if the ignitor is faulty, you should inspect the component for any signs of damage, like cracks or discoloration. If you find the ignitor malfunctioning, it is best to call a professional for assistance. They can help fix the issue and quickly make your home warm and comfortable again.

11. Condensate Pump

If your furnace runs on gas, it will also need a condensate pump to help remove any excess moisture from the system. If the condensate pump fails for any reason, then it may cause the system to malfunction and shut down.

If you see any leaks or moisture buildup around your furnace, it may indicate that the condensate pump is not working properly. Immediately contact a professional to avoid problems like mold or mildew in your home. They will be able to fix the problem and get your furnace running once more.


If your furnace has stopped working, many potential causes could have led to the issue. By going through each of these components and checking for any issues, you can quickly identify the problem. Call a professional technician who can accurately diagnose and fix the issue.

At Honest Air Conditioning, we provide air conditioning and heating installation, maintenance, and repair, among other services. We have highly trained and licensed technicians who are always ready to help with any HVAC needs! Contact us today.