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Grinding, Squealing and Screeching: Interpreting the Noises Your HVAC Makes

If something is failing or going amiss with your HVAC unit, chances are, your HVAC unit is letting you know something is not quite right. However, most of the cues come in the form of sounds that many of us may overlook. If you hear your HVAC unit grinding, squealing, screeching or squeaking, it is letting you know it needs help. I was unaware of these cues and overlooked them. It ended up costing me a lot of money in repairs. I want to make sure that does not happen to other people, so I made this website. I hope you learn how to interpret the noises your HVAC unit is making so you can get it the repairs it needs before you incur a costly repair, or worse, permanently ruin your unit for good.

Grinding, Squealing and Screeching: Interpreting the Noises Your HVAC Makes

2 Possible Reasons Why Your Home's Central Air Conditioner Has Consistently Weak Airflow

by Billie Carlson

If you have noticed that your house feels a little warm even though the air conditioner is running, you may have checked the air coming out of the vents. While the air still feels cold, you may be having trouble feeling it because the flow is weak. Since one of the main causes of weak airflow is a dirty filter or debris obstructing the outside of the unit, you should first change the filter and make sure the system is cleared of debris. If this does not improve the flow of air coming out of the vents, there are a couple of other possible causes, both of which will require the services of an HVAC repair technician. 

1. Evaporator Coils Within the Outdoor Air Conditioning Unit Keep Freezing Over and Blocking Airflow

One possible reason why the airflow coming from your home's central air conditioner is weak is that the evaporator coils keep freezing over. If enough ice forms on the coils, it will block the flow of air. If you try turning off the unit to allow the coils to thaw and the problem keeps happening, there may be a refrigerant leak within the system. If this is the case, you will need a professional to find and fix the leak before recharging the system with more refrigerant.

2. Air Conditioner's Blower Motor Is Failing and Unable to Force Enough Air Through Your Home's Ducts

Another possible reason why you are unable to get adequate airflow out of your home's AC system is that the blower motor is failing. If the motor is unable to move the fan at the required speed or at all, it will not be able to force enough air through the ductwork. 

While standing next to the exterior AC unit, listen carefully to see if you hear any rattling or loud humming coming from it as well as detect a burning smell. If so, this could mean that the motor is going bad and needs the attention of a professional.

If the cool air coming out of your home's vents feels weak and you have already checked for a dirty air filter or debris blocking the external fins of the unit, there is most likely an issue within the AC unit itself. There may be a refrigerant leak that is causing the evaporator coils to freeze over and block airflow, or the blower motor may be failing.

Contact a local air conditioning service to learn.

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