Furnace Repair – Understanding the Basics

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Furnace repair involves electrical, plumbing, gas, and sheet metal work. A basic understanding of industry terminology can help you communicate problems better with experts or even attempt a few minor repairs independently. At its most basic, a furnace converts fuel into heat and distributes that heat throughout the home or office. Its operation is controlled by the thermostat, gas valve, burners, heat exchanger, blower, and air ducts.

Identifying the Type of Furnace

When a furnace malfunctions, identifying its type is crucial to diagnose and find the right furnace repair Staten Island solution. Furnaces come in various styles, each with unique characteristics and repair requirements. Once you have identified your type of furnace, you can gather more specific information about its model and manufacturer. This information will be essential for finding replacement parts or contacting a qualified repair technician. Remember, proper furnace maintenance and prompt attention to minor issues can prevent major breakdowns and extend the life of your heating system. Although furnaces are less complex than major appliances like refrigerators and microwaves, their components perform vital functions. They can also make a lot of noise, including banging, rattling, and irregular hums that indicate something is amiss. Before working on your furnace, cut off its power completely by tripping the circuit breaker or removing the control fuse. This will ensure that no electrical current can reach dangerous or faulty components, such as the igniter and flame sensor. A properly functioning furnace should provide even heating throughout the home. If you notice cold and hot spots, or if your house air feels stuffy and stale, it may be time for an upgrade. Also, if your energy bills continue to rise, consider getting a new furnace.

Inspecting the Furnace

A furnace transfers heat to the air inside a home. This characteristic distinguishes warm-air systems from other types of heating systems. Before any work can be done on the system, it must be inspected to ensure it is safe. This is an important step because if the system is unsafe, it may emit dangerous fumes or pose other safety hazards to the home’s occupants. To begin the inspection, turn off the power to the unit. You can do this by resetting the circuit breaker that controls the heater. This can be found in the main electrical entrance panel or, if the system is fueled by natural gas, at a separate power entrance switch. Remove the fuse if necessary.

Cleaning the Vents and Ducts

Furnaces need clean air to operate effectively. This requires the ducts to be cleaned regularly. An HVAC technician will use specialized tools to clean the supply vents thoroughly and return vents in your home and the ductwork. They’ll also remove and visually inspect the blower motor, heat exchanger, and grilles. The pros have specialized equipment that drastically shortens the time it takes to clean your ductwork and eliminates the chance of damage to the ductwork, insulation, or HVAC connections. They’ll also inspect the ducts for signs of mold growth, infestation, and other problems. They may suggest repairs or additional services as needed. In addition, the professionals will test your carbon monoxide detector. If they detect carbon monoxide, they’ll replace and reset the sensor.

Inspecting the Electronics

Thermostats can face various technical issues preventing their heating signal from transmitting. Some of the most common are a bad control board, incorrect programming, damaged high-voltage wire blocking transmission, and even age-related wear and tear. If your furnace doesn’t feel like producing heat, first check to ensure the thermostat is set to “Heat.” If you can’t get it to start working after guaranteeing this, it could be a problem with the circuit breaker or fuse problem. Locate your home’s breaker panel, find the one that controls your furnace, flip it to the off position, and then back to the on place. If a tripped or blown breaker or fuse is the issue, you should call a professional to inspect and repair your furnace. Attempting DIY repairs without prior knowledge or experience can lead to dangerous consequences that require the help of an expert.

Checking the Safety Switch

There is no better indicator that something is wrong with your furnace than the frequent tripping of its limit switch. This safety device stops the heat exchanger from overheating by detecting the air temperature inside the stove and telling the blower fan to shut off. If you have a volt-ohm meter, you can conduct a simple test to see if the switch is functioning correctly. With the switch plunger depressed, it should read zero resistance. If the meter reads “OL” (infinite resistance), the switch is defective and must be replaced. First, turn off the power to the furnace using the emergency shutoff switch or a circuit breaker controlling it. Then, remove the access panel by removing screws with a screwdriver.


As the temperatures drop and the winter chill sets in, maintaining a properly functioning furnace becomes essential for ensuring a warm and comfortable home. Understanding the basics of furnace repair can empower you to identify potential problems, take preventive measures, and make informed decisions when seeking professional assistance. Whether a simple filter replacement or a more complex issue, arming yourself with knowledge empowers you to confidently navigate the furnace repair process, ensuring a safe and comfortable winter season.