Temperature Talk: 5 Common Gas Furnace Problems (and Solutions)
Is your gas furnace not working properly? Learn about 5 common gas furnace problems and their solutions, from no heat to noisy operation. Get expert troubleshooting tips from Seabright Heating & Cooling.
5 Common Gas Furnace Problems (and Solutions)
It's that time of year — temperatures have dipped and you're using your heating system on a regular basis. Unfortunately, many people find that their natural gas-powered furnace isn't operating properly once they start using it again in the fall or winter. The problem may be fixed with something as simple as relighting the pilot light or replacing the filter, or you may need a more complex furnace repair. Here are five common gas furnace problems, along with possible causes and repairs.
1. Furnace is Not Producing Heat
When your furnace isn't producing any heat at all, there are several possible causes to investigate. The issue could be as simple as a broken thermostat, the thermostat being set too low, or an out pilot light. Other potential causes include a blown fuse or circuit breaker, a closed gas valve, or electronic ignition problems.
How to Fix: No Heat from Furnace
Depending on the cause of the problem, you may need to make sure the thermostat is in "heat mode" and adjust it up a few degrees. If you have a pilot light, try relighting it. Check and replace a blown fuse or tripped circuit breaker. If the problem persists, you may need to troubleshoot the thermostat or electronic ignition problems, which often requires professional assistance.
2. Furnace is Not Producing Enough Heat
If your furnace is running but not providing sufficient warmth, this may be caused by obstructed airflow or dirty or misaligned gas burners. In many cases, airflow is obstructed by a dirty furnace air filter, and simply replacing it solves the problem.
How to Fix: Insufficient Heat
Start by replacing the air filter — this is the most common cause and the easiest fix. If that doesn't solve the problem, have a technician come out to clean and adjust the burners and make sure airflow to the combustion air chamber isn't obstructed.
3. Blower Always Running
If your furnace blower never shuts off, the thermostat may be set to the "fan continuous" setting. In cases where the thermostat has no fan setting, your furnace may have a faulty fan limit control switch.
How to Fix: Continuous Blower Operation
To fix the problem, you might only need to adjust the thermostat fan setting. If the thermostat doesn't have a fan setting or adjusting it doesn't help, it may be necessary to reset or replace the fan limit control switch on your furnace.
4. Furnace Coming On and Off Too Quickly
This behavior, known as "short-cycling," could be caused by a problem with the heat anticipator in the thermostat, a problem with the blower motor, or a dirty furnace air filter. Short-cycling is inefficient and can cause excessive wear on your system.
How to Fix: Short-Cycling Furnace
Start by replacing the air filter. If this doesn't solve the issue, you may need to adjust the thermostat heat anticipator or troubleshoot the blower motor. The blower motor may need to be oiled at lubrication points, or have its belt adjusted (if it is too loose) or replaced (if it is frayed).
5. Noisy Operation
You may be able to determine the cause of a loud furnace by the pitch of the sound it is making. A high-pitched noise may indicate shaft bearings need oiling or that the blower belt is slipping. A low-pitched sound can mean that the pilot light is poorly adjusted or that the gas burners are dirty.
How to Fix: Noisy Furnace
To troubleshoot, try oiling blower motor lubrication ports and checking for proper belt tension and that the belt is not frayed. You can also try adjusting the pilot light and having a furnace service technician clean or adjust your gas burners.
When to Call a Professional
In many cases, troubleshooting and furnace repairs will require the services of an HVAC systems professional. Even if your gas furnace seems to be operating fine now, it's important to schedule an annual heating tune-up to ensure that it will continue to function properly throughout the entire cold season.
Understanding these common gas furnace problems can help you identify issues early and know when to attempt a simple fix versus when to call a professional. Regular maintenance is key to preventing many of these problems. Don't wait until your furnace breaks down completely — schedule annual maintenance to keep your system running efficiently and safely all winter long.
Contact Seabright Heating & Cooling today for professional furnace repair and annual maintenance services. Our certified technicians can diagnose and fix any furnace problem quickly and safely.