Why is my electric furnace humming when off?

Furnace which performs its task normally and correctly didn’t make any noise. But suddenly if you notice humming Noise then you have to consider this problem and find solution that why is my electric furnace humming when off.

Why is my electric furnace humming when off

There are many issues through which your furnace start making noises. So, it’s better to contact with professional in order to check your furnace completely. Because professional contractor checks each and everything of the furnace to check that issue which you told him that why is my electric furnace humming when off.

Why is my electric furnace humming when off?

It’s possible that your electric furnace start making low humming Noise even when off because its happens due to faulty parts. So, you don’t have to take any tension and don’t think too much that why is my electric furnace humming when off because solution of this problem is present.

Just sit back and relax and read this article if you find that you can easily perform this tasks by yourself then perform such task but for electric wiring and ductwork, I recommend you to contact HVAC professional for such tasks. Well, read this article too If you are facing this problem that why your furnace is kicking on when temperature drops.

So, if you wanted to why is my electric furnace humming when off because it happens due to such problem which are mentioned below:

  • Broken or damaged blower motor of furnace.
  • Electric-current in transformer.
  • Loose Ductwork.
  • Too old furnace.
  • Malfunctioning in fan blades.
  • Broken Capacitors.
  • Dirty clogged Air filters.
  • Incorrect Wiring.

Broken or damaged blower motor in furnace:

One of the main cause of why is my electric furnace humming when off is damaged blower motor. Basically, blower motor is used to circulate the air through furnace to the ductwork. This humming Noise is produced by the blower motor when your blower motor is not properly balanced and that’s why it fails to start.

electric motors in why is my electric furnace humming when off

When unbalanced blower motor starts, the humming sound is produced because through this unbalanced motor your unit starts vibrating and in result it starts making humming noise.

A professional HVAC expert is able to solve this problem by adjusting the loose screws and fixing the blower motor accurately until the humming noise stops.

Another reason is worn out bearing of blower motor. Through this reason it starts producing humming and grinding noises. If you are facing the problem by this reason, then one and only solution is replacing your blower motor bearings.

Also read this articles that why furnace blowing cold air because sometimes your furnace blowing cold air instead of warm air in winter. So, this article helps you to understand why this problem happens and what’s the solution of this problem.

Electric-Current in Transformer:

Basically, transformer is used to convert the whole electricity which is coming from the main source in to the proper voltage through which your furnace starts and perform its functions.

If the transformer not performing its task accurately then this issue will cause a humming sound. Because the blower motor starts making humming noise when it’s unable to get the enough power.

Other reason is that fan belt is loose of broken then you need to replace this fan belt because it’s also a reason that blower motor producing humming noise. Well, there are many weird sounds which is coming from the system. So, hire a professional if your furnace producing weird sounds.

Electric current in transformer in why is my electric furnace humming when off

Loose Ductwork:

Always, inspect your ventilation system if you know that no any louder sound is coming from your furnace or its nearby. Because sometimes the humming noise is coming from the loose Ductwork connections instead from HVAC unit.

Basically, air is coming from the ducts of your HVAC system with pressure. So, that’s why the screws which is used to put the ductwork in its place becomes damaged and broken through which air starts leaking and humming sound is produced.

You have to check more loose screws in your furnace or nearby your furnace in order to find that any humming sound is coming from your furnace or not. Employ an expert to complete this task when you believe you are unable of doing it yourself.

Too old furnace:

Sometimes you don’t know why is my electric furnace humming when off. It happens because of old age of your furnace. If you don’t find any issue but still your furnace making humming noise, then it happens due to the old age of furnace.

Because old furnaces produce many weird and unfamiliar sounds. But you know some noises coming due to wear and tear and various other sounds indicates that there are many serious problems in your furnace. If your electric furnace starts making humming noises.

Then, immediately contact with your professional HVAC technician for the complete inspection and for understanding that why is my electric furnace humming when off. Because only certified professionals are able to solve your problems. I suggest you to choose certified professional for your task.

Malfunctioning in fan blades:

Such humming noise is coming from fan blades. Because fan blades starts hitting on the things which is present in the furnace or it’s also possible that something is stuck on the fan blades through which humming noise is coming.

So, if your furnace fan blades are not turning accurately and properly. Then, this is producing humming noise because fan is not able to push all the air from furnace to your house. Its happens due to dust and debris on the fan blades or any other thing which block your fan blades from spinning accurately and freely. Also, if the blades are not properly aligned then it will start producing humming noise.

Instead of just producing humming noise, furnace begin to vibrate. So, in this way it starts damaging other parts of the furnace and in result your furnace faces more difficulties in providing heat to your house. Contact with professional for the complete inspection and for solving this problem.

Broken Capacitors:

Basically, Capacitors help your furnace to start and in performing its basic tasks. But if you find broken Capacitors then immediately replace it with new ones. Because of broken Capacitors the furnace is unable to start and perform its basic tasks. It stops the blower motor from turning completely and starts producing humming noises.

If you notice the low flow of air with continuous humming sound. Then, it means that Capacitors are failed or broken. So, in this situation you have to replace motor and Capacitors in order to again run your furnace smoothly.

Dirty and Clogged Air filters:

Basically, air filters is used to stop all the contaminants which is present in the air. Its stops contaminants like spores, bacteria, mites and dust particles from the air in order to avoid any allergies.

If your furnace air filters are dirty, then you will notice that flow of air is low and your furnace is not performing its heating or cooling cycle smoothly and efficiently.

So, if you find your furnace air filters dirty and Clogged then immediately replace them with the new ones. Because through clogged air filters humming sound is produced. You have to know how often to change air filters of furnace in order to getting better performance from your furnace.

dirty and clogged air filters in why is my electric furnace humming when off

Faulty Wiring:

If there’s any issue with the flow of electricity and wiring in your device is the main causes of producing such humming and buzzing noises. Because it connects with the other parts of the furnace like blower motor and thermostat etc.

Basically, loose wires produce noise like humming because when two bare wires interact with each other then it’s very dangerous because there’s a chance of explosion.

If you find any weird sound like humming or any other sound, then immediately contact with the professional HVAC technician in order to avoid any serious issue from your house.

How much is the furnace repair cost?

Well, furnace repairing cost ranges from $85 to $2100. It depends on what type of issue you are facing and what type of furnace you are using in your house. Few HVAC technicians are going to charge you according to hourly rate and extra fee for some additional work like setting up or for cleaning.

Always, ask with the professional HVAC professional about price details in order to get full estimated price of maintenance service. Also read this article that how much does a furnace replacement cost for proper and clear understanding.

How long does an electric and gas furnace last?

Well, average furnace it might be electric or gas both will run for at least 15 to 20 years by taking proper maintenance. If you are doing regular maintenance and time to time service of your furnace. The lifespan of the furnace can then be prolonged in this manner.

Once your electric/gas furnace reaches its time limit of 15 years then, first of all evaluate your furnace condition in order to check whether your furnace need replacement with the new model or not.


Well, the low humming Noise naturally comes from your furnace but when your electric furnace produces humming noise even when off then there might be some serious problem.

Then, check such things like ductwork maintenance and loose screws, broken Capacitors, faulty Wirings, clogged air filters and transformer.

So, now you understand that if the furnace produces humming noise when off then check your furnace parts that they need replacement or repair.

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