The blower motor that in your furnace has the very important purpose of pushing/circulating air through your ductwork. A furnace blower is made up of an electric motor, fan blades that are encased in a protective cage and the electrical wire connected to the power supply and to the control board that gives the blower operating commands.
Your blower is a hardworking part of the furnace, circulating air when your furnace is in Heat mode and when in AC Mode. Some homeowners prefer to run their blower all the time, setting the Fan on the thermostat to “On” instead of automatic. If you have a newer furnace with an ECM blower motor, running it full-time for air circulation and before dehumidifying in summer might be a good idea.
What Will Indicate That My Furnace Blower Needs to be Replaced?
There are some very obvious signs or indications that your furnace blower will need to be replaced. And it is usually more cost-effective to simply replace the furnace blower, rather than get it repaired. This is due to the fact that once parts on the blower begin to fail, there is a strong chance other parts will fail, and you’ll be “throwing good money after bad” to continue to repair a blower that needs to be replaced.
Below is a list of signs that your furnace blower will need to be replaced:
- Weak airflow through the vents - If you notice that the air coming out of your vents is not as strong as you are used to, this is a good indication that your blower motor is wearing out. There are other possibilities for low air flow, such as a dirty filter or a collapsed air duct, so don’t jump to the blower motor conclusion too quickly. The blower could just need a good cleaning too, or it might be that its capacitor has failed – the little device that kickstarts it – and needs replacing. See our Tips for Increasing Air Flow Through Vents to see if any of these fixes will improve the situation.
- No airflow at all – If your furnace starts in Heat or AC mode and the blower doesn’t, it could be dead. You should also check for a bad relay or battery, control board issues, or problems with the thermostat. You should contact an HVAC technician to check to see if the issue is with the furnace blower or if there are other underlying problems.
- Higher-than-normal energy bills - The furnace blower uses the most energy compared to any other part of your furnace. If you happen to see that your energy bills significantly rise, it could very well be that your furnace blower needs to be replaced. An old blower motor has to work harder to distribute that air through vents, which will lead to higher utility costs.
- Weird/Odd sounds - Any odd or weird sounds that come from your furnace blower compartment probably are an indication that there is something wrong with your HVAC equipment, and some of them related to the blower. If you hear sounds that are “not normal”, you should contact an HVAC technician right away to diagnose and fix the problems. Some sounds, such as squealing or screeching, can indicate that the blower motor has a belt that needs to be replaced or issues with bearings needing to be lubricated. Rattling, clanking, or banging sounds are usually a sign that there is a loose or broken part in your furnace. As soon as you hear a sound that is not a natural sound coming from your furnace, turn the furnace off, and call a trained HVAC technician to either repair or replace whatever is wrong.
- Overheating - There are a number of reasons why a furnace blower may be overheating. If there is a build of dirt or dust around the motor, this can impede it from venting properly. This will cause heat to build-up around the motor, which will lead to overheating. Also, if your blower motor is old, there is a strong chance that it will have to work too hard to circulate the air throughout your ductwork. This strain on the blower will cause your motor to overheat. Some signs that your blower motor is overheating are that you will smell a burning smell coming out of the vents. This is generally followed by the motor completely shutting down.
Pro Tip: If your blower seems to be operating normally but is just loud, consider our page on Tips for Quieting a Noisy Blower Motor.
Also, if you noticed the poor airflow right after replacing the air filter, perhaps the filter you chose has a MERV rating too high for the system. The higher the MERV rating, the denser the filter generally is, and if it is too dense, air flow can be severely hindered.
How Much Will It Cost to Replace a Furnace Blower?
Replacing your furnace blower depends on what kind of furnace you have and the size of blower motor you need. The low-end price for a furnace blower is around $100, and the high-end blowers can cost up to $1,500.
To hire an HVAC technician to come out and replace your furnace blower will cost at least another $200 to $500 for labor depending on the site conditions and the length of time it takes to remove the old furnace blower and install the new blower.