The blower motor is a vital part of your HVAC system. Commonly referred to as an HVAC fan, the blower is what draws air into the system and then circulates the heated or cooled air throughout the duct system. With central heating, the blower motor brings cold air in and forces it over the furnace’s heat exchanger. When your central air conditioning is running, the blower draws in cold air and forces it over the AC evaporator coil.
A new blower motor will typically last for somewhere between 10 and 20 years before the motor wears out and the unit needs to be replaced. However, if you don’t make sure to change your air filter regularly and have your HVAC system professionally maintained every year, your blower motor will likely wear out much quicker. Luckily, there are usually some fairly obvious signs that can help you know if your blower motor is bad or beginning to wear out. Here are the things you’ll want to look out for.
Blower Won’t Turn On
Your blower should always run for the entire time that your furnace or outdoor AC unit is on. If you ever hear these units turn on and the blower doesn’t start within a minute or so, there is a good chance that the blower motor has an issue that requires repair or replacement. We have encountered situations where a blower doesn’t work because it is so caked in dust and debris that it can no longer freely spin.
Most modern blowers have a direct-drive motor with a built-in bearing that spins the fan blades. Blower bearings should last for the lifetime of your unit, but they can also develop issues over time. You will usually notice loud noises as a warning sign when the bearing starts to wear out. Replacing a worn-out blower bearing is fairly easy and much less expensive than replacing the blower motor itself. However, it is essential that you have the bearing replaced immediately and leave your HVAC system turned off until the new bearing has been installed. Otherwise, there is a high risk of the motor burning out.
If your blower is more than 15 or so years old, it may have a belt-driven motor similar to what you’d find in a car. The belt can also wear out and prevent the motor from spinning properly. Replacing a worn-out belt is a relatively simple task. However, we may still recommend that you consider replacing your blower in this situation. Older belt-driven motors are generally nowhere near as energy efficient as new blowers.
Little to No Air Coming Out of Vents
There are times when you may notice that there is little to no airflow coming out of your vents despite being able to hear that the blower is running. This could indicate that your blower motor is beginning to wear out and can no longer circulate air through your HVAC system efficiently.
The first thing to do in this situation is to make sure that your air filter doesn’t need to be replaced. If the air filter is overly dirty and caked with dust and debris, it becomes almost impossible for the blower to draw air in through the filter. As a result, you’ll have decreased air blowing out of your vents. A dirty air filter puts a huge amount of strain on the blower motor since it has to work much harder to draw air in. This has the potential to quickly cause the motor to overheat or burn out, which is why it is essential that you replace your air filter once every four to 12 weeks.
If you still have insufficient airflow after replacing the air filter, we recommend having your HVAC system inspected as soon as possible. It could be that your blower motor is starting to wear out or that your ductwork is damaged and leaking air.
Higher Than Normal Electricity Bill
As a blower motor starts to wear out, it will usually need to work much harder and draw more electricity than normal. If your electricity bill suddenly spikes in the summer, the culprit could be a worn-out blower motor or damaged AC component. If you notice a sudden, unexplainable spike in your electricity bill during the winter when your furnace is running, you need to have your blower motor repaired or replaced.
Burning Smell Coming From Air Handler or Vents
If you ever notice a burning smell coming from your air handler or blowing out of your vents, you should immediately shut off your HVAC system. This smell often indicates that the blower motor is overheating, which can lead to its wires beginning to melt. An overheating blower motor is a serious problem as it has the potential to catch fire. Although most HVAC systems have a safety switch that is designed to automatically shut everything down in the case of overheating, this switch can sometimes fail.
A blower motor can overheat for a variety of different reasons, including a clogged air filter, dirty ductwork or because the blower itself is overly dirty. The motor will also start to quickly overheat if its bearing is worn-out and you try to run your HVAC system. Many times, the issue that is causing the motor to overheat is fairly easy to fix. However, we would always recommend having this problem inspected immediately. This prevents the motor from failing and needing to be replaced.
Loud or Unusual Noises
A blower motor may start to produce loud or unusual noises when it experiences any issues. If you notice that your blower is suddenly much louder than normal, it usually indicates that the motor is working harder and struggling to keep up.
If all you hear is a loud buzzing or humming noise coming from the blower, the unit’s bearing or belt may be worn-out and in need of replacement. A loud screeching or grinding noise often indicates that a bearing is starting to wear out. This is a noise you should take seriously to prevent your motor from burning out. A shrill squealing sound coming from the blower can indicate that the unit’s belt is misaligned, starting to wear out or needs lubrication. It’s a similar sound as when the belt in your car wears down.
Replacing a worn-out or damaged blower motor can be somewhat costly, but it is still something you will want to do as soon as possible. If not, you run the risk of causing serious damage to other parts of your HVAC system. This ultimately will increase the cost of your repair bill. If you do notice any signs of a bad blower motor, the technicians at AJ Danboise Plumbing, Heating, Cooling & Electrical can inspect the unit and determine whether the issue can be repaired or if a blower replacement is necessary. We also install, service and repair air conditioners, furnaces and boilers. We offer a full range of plumbing and electrical services as well. To schedule a blower inspection or any other home HVAC service, give us a call today.
