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7 Ways to Troubleshoot a Malfunctioning Furnace

7 Ways to Troubleshoot a Malfunctioning Furnace

There is nothing worse than coming home to a cold house after a full day at the office or school. If your furnace is not working, this may be due to issues with the preset thermostat settings or a variety of other hardware components. Prior to calling a professional HVAC technician, we recommend troubleshooting the furnace to confirm if the issue is able to be resolved with a simple fix. We have created a list of 7 steps to follow when you are troubleshooting a defective furnace in your home.

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Why Is My Furnace Not Working?

1.) Check the Circuit Breaker Panel for a Tripped Circuit Breaker

If your furnace is not turning on, the first step to troubleshoot the issue is to check the thermostat to ensure the “Heat” mode is activated. Next, toggle the temperature switch or increase the temperature a few degrees to a setting that is higher than the internal temperature of your house. If the gas or electric furnace is not turning on, this may be a sign of a tripped or blown circuit breaker or fuse.

Navigate to the circuit breaker panel in the garage, laundry room, or storage area of your house. Next, open the panel and search for the circuit that controls your gas or electric furnace. If the circuit has been toggled to the “Middle” position, this is due to a tripped circuit breaker. To troubleshoot the furnace in your home, toggle the switch to the “Off” position. Next, flip the switch to the “On” position to successfully reset the breaker.

If this furnace troubleshooting method does not resolve the issue, the electrical wiring in the circuit may be malfunctioning. Or, there may be an issue with a component in your furnace. Give us a call by phone at (484) 206-8594 to receive assistance. WM Henderson offers furnace repair, tune-up, installation, and replacement services to homes in West Chester and other areas of Pennsylvania.

High-Efficiency Furnace2.) Inspect the Electronic Ignition System or Pilot Light

The furnace in your home may not be working due to a faulty electronic ignitor or pilot light. While older gas furnaces rely on a standing pilot light to activate the combustion process, modern furnaces include an electronic control system. This type of ignition system provides superior performance and helps conserve energy.

Types of Electronic Ignition Systems

The two types of electronic ignition include intermittent pilot and hot surface ignition systems. An intermittent pilot system produces an electronic flare to activate an internal pilot light and gas burners. On the other hand, a hot surface system utilizes a heating element that is powered by electric to activate the gas burners on a furnace.

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Problems With Intermittent Pilot Lights

If your furnace with an intermittent pilot light system is not working, troubleshoot the furnace by performing an inspection to confirm if you notice malfunctioning ignition components, damaged pilot lights, or broken gas burners. Refer to the instructions provided by the manufacturer to replace damaged components in your gas furnace. To avoid a potentially dangerous gas leak, we recommend scheduling a furnace repair appointment with our team. Give us a call by phone at (484) 206-8594 or schedule an appointment online to receive help.

Problems With Hot Surface Ignition Systems

Gas furnaces with hot surface ignition systems include an electronically controlled component called a hot surface ignitor. This component relies on electricity to produce heat energy and is installed near the gas burners. Once a digital thermostat activates the furnace, electricity is transmitted to an electronic ignition module that is integrated with the central fan. 

This compartment will send electricity to the main hot surface ignitor in the gas furnace. The incoming electrical supply is used by the ignitor to produce heat. Next, a gas valve in the heating system is activated to allow for a successful transmission of gas to the main burners. As the gas is released, it is ignited by the hot surface ignitor to produce a sufficient supply of warm air for your home. Once a flame is produced by your furnace, a flame sensor is utilized to detect the flame and deactivate the hot surface ignitor.

If your furnace is not turning on or working, this is an indicator of a cracked or damaged hot surface ignitor in your gas furnace. To receive assistance troubleshooting or replacing a hot surface ignitor, contact our team of licensed technicians. We offer furnace repair and installation services to homes in areas of Pennsylvania such as Drexel Hill, Havertown, Wayne, and Ardmore. 

Boiler Repair3.) Check the Safety Switch of the Furnace

When the furnace is not working in your condominium or home, this may be caused by a manfunctioning safety switch. A safety switch is a component located near the door of the furnace that is designed to deactivate the combustion process and fan while the front panel is detached.

Since the heat switch prevents the formation of flames and heat while the front panel of the furnace is off, it prevents potentially harmful health consequences such as moderate to severe burns. As a safety switch reaches the end of its lifespan, it may begin to malfunction and prevent the furnace from turning on.

To replace the safety switch, deactivate the power to your gas furnace. Next, connect each of the wires on your new safety switch to the central gas furnace. Lastly, activate the furnace to confirm it is able to start the standard heating process. To avoid damage to your heating system, we recommend hiring a professional to perform all furnace troubleshooting and installation steps. WM Henderson offers heating repair, tune-up, and replacement services to homes in Pennsylvania.

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4.) Inspect the Flames Produced By the Burners

Another common gas furnace problem is dirty burners. When dirt and foreign objects become stuck in the burners, the heating system will struggle to produce heat for your home. If the burners are producing yellow flames, this is a clear indicator it’s time to get the furnace cleaned by a professional. When a burner is clean, it will produce warm and consistent blue flames.

You can easily sanitize the burners by using a vacuum and various other tools. Prior to beginning, deactivate the supply of electricity and gas to the furnace. During the warmer months of the year, moisture and dirt will collect on the furnace while it isn’t being used. 

It’s vital to remove all dirt, soot, and objects from the heating system. Once the burners are clean, it’s important to reconfigure all parts and components prior to activating the furnace. We recommend scheduling an annual furnace tune-up and cleaning appointment with our team to avoid furnace problems. When your furnace is not working, give our team a call by phone at (484) 206-8594 or fill out our Appointment Form to receive support.

Furnace5.) Inspect the Furnace Limit Switch

The furnace in your home utilizes gas and fans to push warm air throughout the air ducts. The burners in a gas furnace are engineered to provide heat to the heat exchanger component. As incoming air travels through the heat exchanger, it’s temperature changes to accommodate the data sent from the thermostat.

The incoming air will need to be processed by the heat exchanger prior to being circulated around the home. To ensure the air is warm prior to distribution, a limit switch that includes a sensor is activated. The sensor is located in the heat exchanger of the gas furnace. Limit switches are designed to ensure the temperature of the incoming air is sufficient prior to being pushed throughout the home.

Once the temperature of the air is sufficient, the limit switch will activate the blower on the gas furnace to transmit the air in your home. If your furnace blower is not working, this may be due to an issue with the fan limit switch. You will be required to replace this switch with a compatible component to fix the system. Give our team a call by phone at (484) 206-8594 if you need help with a furnace that is not working.

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6.) Clean the Flame Sensor on the Furnace

The flame sensor is a rod on a furnace that is located near the gas burners. It is engineered to ensure gas is being processed in a safe manner throughout the combustion procedure. If the furnace in your house is not working, a contaminated flame sensor may be the culprit.

To improve the performance of the furnace, you will be required to clean the flame sensor to ensure it is able to accurately detect and monitor the flames produced during the heating process. First, navigate to the circuit breaker box in your home and deactivate the power to the heating system.

Next, remove the flame sensor from the gas furnace prior to sanitizing it. We do not recommend cleaning the sensor while it is installed. This may cause damage to the internal components near the sensor. Once the sensor is removed, use a sponge or towel to remove dirt, dust, and other materials. Lastly, install the flame sensor to its proper location and activate the furnace. Is your furnace not working after performing this repair? WM Henderson offers furnace repair, replacement, and tune-up services to homes in Coatesville, Conshohocken, Broomall, and West Chester, Pennsylvania. Give us a call by phone at (484) 206-8594 to book an appointment.

Air Filter7.) Check the Air Filter

If your furnace is continuously activating and deactivating in a short timespan, this may be a sign of a clogged or dirty air filter. We recommend deactivating the furnace and replacing the air filter. Next, active the furnace and perform an inspection to confirm it is no longer deactivating.

Are you still having furnace problems after switching the air filter? Other possible issues that may cause short-cycling include deteriorated flame sensors or clogged air ducts. In addition, this issue may be due to a sizing issue. If your furnace is too large or small for your house, this may cause short-cycling problems. Do you need assistance replacing flame sensors in your furnace? WM Henderson offers reliable and affordable heating repair and installation services to homes in Pennsylvania.

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Reliable Furnace Repair, Tune-Up, & Installation Services

If you’ve tried each of the do-it-yourself repair methods above and your furnace is not working, it’s time to call a professional on our team by phone at (484) 206-8594. WM Henderson offers furnace repair, tune-up, and maintenance services to homes in Pennsylvania in areas such as West Chester, Coatesville, Conshohocken, and Broomall. We also offer other heating services including for boilers, heat pumps, and ductless mini-split systems. Schedule an appointment online to receive assistance.