A furnace does a lot of work through the long and cold winters in the Twin Cities. Even with the best maintenance, a furnace can still run into a malfunction that will weaken its heating ability or cause it to stop working altogether.
You never want to attempt to do any repairs on a furnace yourself—you’ll need to call the experts at Residential for heating repairs in Minneapolis, MN. We have many experiences dealing with all types of furnace malfunctions, and we know how to resolve them. Let’s look at five of the most common furnace problems we’re called on to fix. This list will help you better understand how your furnace works and what might cause it to stop working.
1. Ignition Problems
For decades, the way a gas furnace ignited the burners to start heating the air was with a standing pilot light. A few older furnaces still have these, but the newer models use more energy-efficient electronic ignition systems.
These systems are more dependable than pilot lights, but they can still fail, such as cracking because of heat. The furnace won’t turn on if the igniter isn’t activating the gas jets. The igniter isn’t activating the gas is often a sign of deeper issues.
2. Faulty Flame Sensor
The reason a gas furnace will shut off if the igniter doesn’t light the burners is because of a safety device called the flame sensor. (In older furnaces, a simpler device called a thermocouple did the same job.)
If the flame sensor doesn’t detect that the gas jets have been lit, it will shut the furnace off to avoid flooding the combustion chamber with unburned gas. But if the flame sensor malfunctions, it will stop the furnace from turning on no matter what! Professionals can safely repair or replace the flame sensor.
3. Malfunctioning Blower Motor
The blower fan is responsible for pushing air from the return ducts through the furnace for it to be heated and then continue into the ductwork to the rooms. The motor that powers the blower can fail because of overwork or excess dust, and this sometimes starts with a tripped circuit breaker.
A failed blower motor will cause the furnace to soon overheat and trigger the load limit switch to shut the furnace down. Leave any work with the blower motor to HVAC experts.
4. Dirty Burners
Dust and debris can infiltrate the furnace cabinet (especially if the furnace filter is clogged) and coat the burners. This will make it harder for the burners to access enough oxygen and ignite. You’ll start to hear delayed ignition or the furnace won’t ignite at all because the flame sensor will keep shutting it off. The furnace won’t ignite at all is a symptom worth investigating.
5. Electronic Malfunctions
Even gas burners rely on numerous electrical components to operate, such as the control board that allows the different parts to work in conjunction. Electrical failures are a common problem and will often cause the furnace to fail to turn on—or possibly fail to turn off. You only want technicians to work on complex electrical parts of your furnace.
Frequently Asked Questions
Question: What ignition problems commonly occur in modern gas furnaces?
Answer: Modern furnaces often use an electronic igniter instead of a standing pilot light. The igniter can crack, malfunction, or fail due to heat or electrical issues, preventing the furnace from lighting. When the igniter fails, the furnace won’t start the burners.
Question: What is the role of the flame sensor, and how can it cause furnace problems?
Answer: The flame sensor is a safety device that detects whether the burners are lit. If it fails to confirm a flame, it shuts off the furnace to avoid unsafe gas build‑up. A dirty or malfunctioning flame sensor can prevent the furnace from operating at all.
Question: How can a blower motor malfunction affect the furnace’s performance?
Answer: The blower motor pushes the heated air through ductwork. If it malfunctions, due to overwork, dust buildup, or electrical issues, the furnace can overheat, trip safety switches, or shut down due to lack of air flow. Proper airflow is essential for safe operation.
Question: Why do dirty burners cause issues in gas furnaces?
Answer: Dust and debris on the burners can interfere with proper combustion by restricting oxygen. This leads to delayed ignition or misfires, which can trigger safety sensors (like the flame sensor) and may prevent the furnace from igniting. Regular cleaning helps.
Question: What kinds of electronic malfunctions are often seen in furnaces, and why are they dangerous or disruptive?
Answer: Furnaces rely on various electrical components like control boards, sensors, and ignition systems. Failures in these parts can prevent the furnace from turning on, turning off, or maintaining safe operating conditions. Because of safety and complexity, these problems usually require professional repair.
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