Troubleshooting AC noises: Orlando HVAC contractor or DIY?

HVAC Logo IconBy HVAC.comAugust 1, 2023
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Hearing strange noises from your air conditioner? An Orlando HVAC contractor may be needed, but there are a few steps you can take before making the call.

AC makes bubbling noise

If a bubbling or gurgling noise is coming from near the outdoor unit, the drain line could be blocked or clogged. The drain line is a PVC pipe that’s attached to the indoor unit and runs outside your home, stopping near the condenser (outdoor unit).

A refrigerant, or coolant, leak may also sound like a bubbling or hissing. If a leak is the problem, then your AC may also be blowing warm air or running constantly.

DIY or call an HVAC contractor?

If the drain line is making the bubbling noise, try some at-home HVAC cleaning. Using a stiff, wire brush, push through the drain line and break up any debris.

If the noise continues after you’ve cleaned the AC drain line, we suggest calling a technician.

Refrigerant issues require professional care. It’s unsafe (and illegal) for anyone not certified in dealing with refrigerants to attempt the repair.

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Rattling noise

A rattling noise usually points to loose debris in the outdoor unit. There may be leaves, dirt, or sticks clanging against the unit.

A more serious scenario may involve a broken fan or aging parts that have loosened over the years.

DIY or call an HVAC contractor?

Before calling an Orlando HVAC contractor, you can try to break up the loose debris. Turn off the power at the circuit breaker before touching the AC unit.

With gloved hands, pluck any loose leaves or sticks out of the air conditioner. If any debris is still stuck, spray down the air conditioner with a garden hose.

It’s important not to clean an air conditioner with a pressure washer. The water pressure is high enough to damage the delicate outer fins.

If the rattling is coming from the air handler (indoor unit in attic or basement) or vents, reach out to an HVAC contractor.

Hissing noise

A hissing noise inside the home usually stems from air leaking out of your ductwork. There may be gaps, cracks, or seals in the ducts.

Air handlers can also make hissing noises when they leak refrigerant. You would likely hear the noise coming from your attic or basement.

DIY or call an HVAC Contractor?

Before calling a technician, check the ductwork for any cracks or gaps. You can seal minor gaps with duct sealant for less than $10.

If you see major ductwork leaks or suspect a refrigerant leak, we suggest calling an Orlando HVAC contractor. Refrigerant leaks are a safety hazard, and handling refrigerant requires a special certification.

Clicking noise

If the clicking noise happens while the AC is on and running, the fan blades may be bent or broken. If your AC won’t turn on and you hear a repetitive clicking noise, there is likely a wiring issue or a malfunctioning thermostat.

DIY or call an HVAC Contractor?

Neither of these issues has a DIY solution. Fan blade and wiring-related issues are best left to professionals, as they require special certifications.

How Much Does HVAC Replacement Cost?

Average Cost: $3,250 – $12,586

Like your home and needs, your HVAC project cost will be unique. Use the calculator to better estimate your investment.

*Estimate is based on current data and does not represent a guaranteed price. For accurate pricing contact a local HVAC dealer.


$5,000 – $6,000

Estimated Total

The average cost for a new HVAC system is $3,250 to $12,550, which includes equipment and labor fees for the installation of a central AC unit and gas furnace. The chosen HVAC brand, necessary ductwork repair, and your location will influence the project cost.

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Banging or knocking noise

A banging noise usually indicates a compressor issue. The compressor helps keep refrigerant moving through the HVAC system. If you have an older AC, the components that make up the compressor may have become loose.

There may also be an issue with the fan. The fan blades may have come loose, and the knocking sound is the fan hitting the inner cabinet. A foreign object may have also entered the air handler cabinet.

DIY or Call an HVAC Contractor?

If the banging or knocking noise is coming from the outer unit, call an HVAC contractor to assess the issue.

If the banging is coming from the air handler, or indoor unit, you can try troubleshooting. Disable power at the circuit breaker and open the air handler.

Your air handler manual should have instructions on how to open the cabinet. You may need a screwdriver set, a nut driver, a drill, and a wrench.

Check the cabinet for any foreign objects. If anything is blocking the fan, remove the item. If nothing in the cabinet is out of place, call an HVAC contractor or technician.

Orlando AC tune-up

Many of the AC issues that cause strange noises are preventable with regular maintenance. An AC tune-up prepares your system for heavier use in spring and summer.

During an AC tune-up, the Orlando HVAC contractor will:

  • Inspect electrical wiring
  • Check the evaporator coil, compressor, and capacitor
  • Clean the drain pipe
  • Inspect the control board
  • Measure refrigerant levels
  • Inspect ductwork

Need an AC tune-up stat? Let’s connect you with top-rated HVAC contractors in your area.

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