HVAC Troubleshooting: What is Causing My AC’s Loud Buzzing Noise?

Why Is My AC Buzzing? Loud AC buzzing noise from an AC unit indicates stress on a HVAC system, specifically an electric issue.  It is important that you do not become familiar with the noise, and instead turn off your AC unit and call a licensed HVAC contractor. It is also important to distinguish the noise from rattling or grinding, as those sounds are a typically signs of malfunctioning parts, debris or misalignment.


AC Buzzing noises are usually from electrical arcing – a discharge when electricity is jumping between circuitry. Loud buzzing noises indicate the electrical voltage flowing through your air conditioner is not at its correct amperage. Failing electrical components increases the risk of fire and should be diagnosed by a licensed HVAC expert to keep you and your home safe.


The motor needs to be lubricated with oil, especially in older AC units, to keep bearings from getting worn and eventually malfunctioning. A bent blade on the fan could also cause a buzzing noise. Lubricating the motor or replacing fan blades should be done before extensive use of AC (at the beginning of summer for example) to prevent a malfunctioning system later on.


If a buzzing or hissing noise is coming from the AC unit itself, it could be a sign of a refrigerant leak. Refrigerant leaks cause AC units often freeze up, even during the hottest time of year when the AC is consistently on. Water dripping onto the motor will cause also an abnormal noise; the repair would involve locating the obstruction/leak and properly isolating the unit.


AC Buzzing NoisesThis is associated more with a rattling noise, but misalignment or loose screws/panels could also create a ‘buzzing’ noise. Poor installation or aged AC parts cause screws to become loose, also causing the panels on the cabinet to unfasten.

At Action Air Conditioning, Heating & Solar we care about your comfort and savings. We guarantee convenient and efficient service for all maintenance and repair calls. Did you know 90% of all HVAC breakdowns are caused by lack of maintenance?  Don’t put your comfort on hold, Call or Schedule Your Maintenance or Repair Appointment Today!




Prevent problems like buzzing and others in the future by signing up for our maintenance program

What Can You Do About Blocked Drains?

Air conditioning repair Poway CA - blocked drains Irregular and erratic maintenance can backfire at you in many ways. Regular system check-up and maintenance is the best way to ensure your unit performs well and reliably for many years to come. Maintenance will also prevent costly and extensive air conditioning repair Poway, CA (and any other area). Here’s what you need to know about blocked AC drains.

What are condensate drains and how do they function?

Dehumidifying the air is vital for efficient air conditioning, because dry air holds less heat energy. Your central AC unit draws in warm air from your home, pulls it through the chilly evaporator coils to cool down and blows it back inside. While the air is around the cold evaporator coils, condensation is formed. Since it won’t go away on its own, this water is collected in the drip pan under the coil. The drip pan or collector pan is slightly tilted, so the collected water can move more easily into and down the drain pipe and out of your home.

When your AC is in fine condition, the drain will only leak when the AC is operating and the puddle that forms outside should be small. However, if you notice that the condensate drain is leaky even when the AC is off, inspect the AC immediately for signs of blocked drain.

What can go wrong if you ignore blocked drains?

Blocked drains are not something you want to ignore. There could be many consequences, some of them rather severe, such as:

  • Water damage
  • Toxic mold (related to water damage)
  • Bad air quality
  • System breakdown
  • Fire (because of water flooding the electrical components)

What causes blocked drains?

In the majority of cases, it’s because not only water is flowing through the drain line. Dust and bacteria can also find their way into the line. When these two combine with water, you get gunk and sludge which accumulate and block the passage through the pipe. This can happen because the air filters are dirty or simply inefficient and allow too many dust particles to enter the system. On the other hand, even a small amount of bacteria or mold inside the drain would breed rapidly due to conducive conditions, ultimately causing a blockage.

How can you clean blocked drains?

Turn off the AC at the thermostat and the breaker. Check the drip pan just under the indoor air handler unit and the evaporator coils. If it’s overflowing, that’s a clear sign of a blocked drain line. Remove the water by soaking it up with some cloth or vacuum it with a wet/dry vacuum.

Condensate drains, especially those in residential units, are generally made from PVC, which is chemically-resilient. For a long time, the prescribed DIY cleaning solution was a 1:1 mixture of hot water and white vinegar (or bleach). In standard-size single-family homes, 2 cups of the solution should be enough. However, you should note that recommendations have recently changed, because different materials are being used in AC manufacture now. Chemical vapors from white vinegar and bleach could cause premature oxidation and degradation of the materials. You can simply use hot water instead – pour it slowly at the T-shaped vent on top of the drain.

You can also use a wet/dry vacuum, but at the end of the drain pipe. You can first vacuum the pipe and then pour hot water down the pipe.

Cleaning the drain pipe is part of regular professional maintenance. If you sign-up for this service with us, we’ll ensure your drain pipe is clear from blockages and clean.

When you need air conditioning repair Poway, CA, Action AC is here for you!

The best prevention of blocked drains and related problems is regular professional maintenance. Action AC has been serving the local San Diego community since 1975 with unparalleled success. We’re the most awarded AC specialists in San Diego. Thousands of San Diegans have entrusted us with their comfort because we offer utmost professionalism and premier customer care. Call us for all AC maintenance, service and repair you need, whenever you need it – we’re just a phone call away!

Is Your House Haunted or Is It Just Your Faulty Air Conditioning Chula Vista?

Ghosts or air pressure problems with air conditioning Chula Vista Sometimes, malfunctions with HVAC aren’t that easy to pick up on. Your system could be heating or cooling your residential or commercial space quite well, but it could be having problems with air pressure. Regulating air pressure in a space is one of the advantages of having a centralized air conditioning system, such as HVAC. So, when is your HVAC telling you to call professionals who specialize in repairing air conditioning Chula Vista and San Diego?

Is that what I think it is?

Here are some unusual symptoms of HVAC problems.

  • Doors open on their own.
  • Doors slam by themselves.
  • Unexpected drafts of air.
  • Doors are difficult to open.
  • Rooms are surprisingly hot or cold.
  • You can hear whistling sounds and strange noises.

Even though these symptoms look like a clear case of a ghost haunt, it’s most likely your HVAC is acting up because of an imbalance in air pressure.

What problems are associated with air pressure imbalance?

Problems with positive air pressure result in air pressure which is higher in your home, office and commercial space than it is outside. Air flows from high pressure zones to low pressure, because pressure is force. That means your precious cooled air will leak from your home or commercial space through every hole and pore it finds. The positive pressure will also make outward-opening doors fly open and vice versa – opening doors that open inward will feel like weightlifting.

Negative pressure is the opposite. The air from the outside will be sucked in again through any existing air leak and there will be similar problems with doors. Doors opening inward will fly open, while those opening outward will be difficult to open. There’ll also be a strain on your air conditioner and furnace to work harder to maintain the temperature set, which will reflect in mounting energy bills.

What’s causing air pressure problems with your air conditioning Chula Vista?

Hot air that goes up can cause a negative pressure in the lower level of your home or commercial space. This can happen with large fireplaces and combustion appliances.

Exhaust fans can produce the same effect like combustion appliances. Negative pressure can cause backdrafting, which is undesirable when you have wood-burning stoves and chef-range stoves as it can lead to accumulation of carbon-monoxide.

Fan motor speed that is set too high can blow too much air in a room, resulting in high pressure.

Leaky ducts are very problematic and can make for differences in air pressure across your residential or commercial space. In some rooms the pressure can be high, while at the same time it can be lower in other rooms. As we have said, leaky ducts are huge energy suckers that will hit you in the hip pocket month in, month out.

Call Action AC for all and any problems with air conditioning Chula Vista and San Diego

Action AC is one of the top rated air conditioning companies in San Diego. With more than 4 decades of industry experience under our belt, outstanding customer service and a full range of services for residential and commercial HVAC systems, we are sure we can cover all your needs for air conditioning Chula Vista and anywhere else in San Diego. Call us 24/7 at (760) 727-4152 – we are always here for you.

Why HVAC Maintenance Is Critical to Your Home & Energy Bills

Did you know that 90% of all HVAC system malfunctions or breakdowns are caused by a lack of maintenance?

The best thing you can do for your heating and cooling system is to have a reliable NATE Certified technician perform regular service on it. Unmaintained gas furnaces, especially older models, are a safety hazard and could be potentially put you, your family, and home at great risk.
An Action Air NATE-Certified technician discovered this entire house was at severe risk for fire and carbon dioxide poisoning after receiving a routine repair call about a furnace not producing heat.
This can potentially happen to you. If you notice anything out of the ordinator about your HVAC system, it is important to immediately call an HVAC contractor, like Action Air.

Here are a few signs your furnace could be putting you and your home at risk:

  • Smell of burning coming from HVAC after heat is turned on
  • Strong smell of fuel
  • Carbon dioxide monitor goes off
  • No heat is being produced
  • Utility bills increase
  • Your HVAC is making loud or unusual noises (rattling, buzzing, banging)

Having your HVAC system regularly serviced (2 times per year) is the best way to ensure your furnace is safe and reliable. Additionally, regular maintenance will improve your home’s indoor air quality, enable your system to operate at optimal performance, reduce energy costs, and mitigate expensive repairs.

If you have not had routine ac or furnace maintenance performed this season, contact Action Air today to schedule your Quality Maintenance inspection for only $50* out of pocket. Our team is dedicated to your home’s safety and comfort and is available to you 24-7 through our on-call Emergency Service.