Imagine waking up on a frigid January morning to a home that’s as cold as ice. Furnaces usually stop working in the dead of winter when they’re under the greatest amount of stress. This can be highly inconvenient and potentially dangerous for you, depending on the climate in your area.
Fortunately, HVAC systems almost always exhibit certain warning signs before they go out completely. If you heed them, you can head off trouble at the pass. From strange smells to rising energy bills, here are five indications your furnace needs immediate repairs.
1. Unusual Smells
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It’s normal for your furnace to release a burning odor when you first turn it on for the year. This happens because the system gathers dust during the off-season. When you turn the unit on the first time, it burns up the dust and sends slightly stinky air through your vents. This smell should dissipate completely within the first few hours of operation. While burning dust is harmless, other scents could indicate a serious problem with your furnace.
If you smell a musty odor or a rotten egg aroma coming from your air vents, turn the unit off immediately. A musty scent usually indicates the presence of mildew or mold. These are often caused by a broken or clogged condensate drain line and must be addressed by a professional. A rotten egg smell is an indication of a natural gas leak that could be life-threatening. Exit your home immediately and call your natural gas company or 911 if you ever notice this odor coming from your air vents.
2. Abnormal Sounds
In general, your furnace should be fairly quiet during operation. You may hear it kick on and easily detect the sound of air being pushed through your vents. But there shouldn’t be any rattling, knocking, or squealing sounds when the unit is operating. If you do hear strange noises while the furnace is on, it’s time to schedule an appointment for diagnosis and repair.
If your HVAC system makes a squealing noise, you may have a damaged belt or another problem with the blower motor. Booming or banging sounds could be indications of delayed ignition due to a weak flame, defective ignitor, or burner malfunction. You will likely need an expert to help you locate and repair the source of the issue. If you hear rattling sounds, there might be a broken part rattling around in your furnace. An HVAC technician can help find the part and fix it.
3. Rapid Cycling Times
When your furnace kicks on, it should complete a full heating cycle before turning off. If you notice that it keeps cycling on and off too rapidly, you’ll need to have it looked at. The tricky thing about short cycling is that it could have many potential causes. Some of the possibilities are very easy to fix, while others might require more complex repairs.
If your furnace rapidly cycles on and off, check your flame sensor. If it’s dirty, it won’t be able to detect when the burners are lit, which can cause short cycling. A clogged filter can also prompt cycling problems by leading the furnace to overheat. Issues with the ignitor or burners can likewise make the furnace cycle improperly. Identifying and fixing the problem early on is essential for avoiding more costly repairs down the road.
4. Abnormal Burner Flame Color
It’s wise to periodically inspect the color of your burner flame when your furnace fires up. If everything’s working properly, the flame should have a nice blue hue. It’s perfectly fine if you see a tiny bit of yellow near the tip of the flame. However, if the majority of the flame is any color other than blue, you have a potentially dangerous problem.
A yellow or orange flame is never a good sign in a furnace fueled by natural gas. These colors indicate that the unit isn’t burning off the gas completely and is likely producing carbon monoxide. CO is a tasteless, colorless gas that can cause nausea, headaches, and even death by carbon monoxide poisoning. Turn off your furnace, leave your home, and call a technician immediately if you notice a yellow or orange flame.
5. Changes in Airflow
Your furnace has one main job: to move warm air throughout your home. If it is unable to do this efficiently, it won’t heat your home evenly. Problems with airflow may be subtle and difficult to detect at first. You may first notice that the flow of air coming through your vents seems weaker than usual. This is an indication that your furnace isn’t able to push out air effectively.
In some cases, airflow changes could be caused by a dirty filter. Simply changing the filter could rectify the issue and restore the proper flow of air. In other cases, leaky ductwork, a clogged blower fan, or other defects could be causing your furnace to work inefficiently. Scheduling repairs right away could help prevent the problem from becoming more serious (and expensive).
It’s easy to take your furnace for granted — until it stops working in inclement weather. Fortunately, you can avoid getting left in the cold this winter by simply paying attention. Learn how to recognize early signs of common furnace issues so you can schedule repairs before your unit gives up the ghost.