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.

Electrical

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.

Motor

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.

Refrigerant

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.

Parts

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!

 

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HVAC Troubleshooting: Why is My AC Rattling?

When you hear your AC rattling, it is a good indicator that something has gone awry with your HVAC system. Ignoring the issue will create expensive repairs, so make sure you schedule a maintenance, tune up, or repair appointment with a licensed HVAC contractor. There are several situations that could cause a rattling noise – it could be an easy fix such as tightening screws, or it can be an indicator of malfunctioning parts which can become very expensive if gone unrepaired.

Debris

When the filter has not been changed for a while and becomes clogged, dirt, sticks, leaves, gravel and other types of debris can enter the AC cabinet and get knocked around. A dirty AC filter can cause serious damage to the AC’s parts/components along with a variety of other issues, and should be fixed immediately to prevent any more debris from entering.

Panels

Poor installation or aged AC parts can cause screws to become loose, which cause the panels on the cabinet to unfasten. This is common with old HVAC systems, which should be maintained at least twice a year.

Fan

Rattling caused by the fan within the AC unit could be from the blades themselves can becoming loose, especially in older AC models. Luckily, fan blades are easily replaceable. If the fan is misaligned due to debris or age, it will progressively get worse and eventually cause the fan to stop functioning. Dirty blades can also cause noise, so it is important to keep the blades clean and make sure your AC filter is changed regularly.

Motor

The compressor is the ‘heart’ of HVAC system, and when its parts become loose it can cause a total system breakdown. This is more common with older HVAC systems. When the noise increases from the compressor, it is usually a strong sign the compressor’s hardware needs replacing.

Installation

An unstable AC unit is a common source of rattling noise. Improper installation can cause parts to be more susceptible to damage. The noise could be from the damaged parts or by the AC unit or the platform not lining up with a window sill. Re-installation can easily fix the rattling if you notice loose/shifty parts.

Preventative maintenance can fend off unwanted repair bills and inconvenient HVAC malfunctioning during the months you use it the most. Call us today to learn more about our Precision Tune Up Program or to schedule an appointment for repair with one of our NATE-certified technicians!