Crash, Bang, Hiss: Commercial HVAC Noises

Unlocking the door to your normally quiet office, you notice there’s an odd noise coming from inside. It sounds like something is scampering around in the ceiling. That’s when you realize that odd rattling sound isn’t a mouse making its way through the air ducts; it’s your commercial HVAC. You know that sound can’t be good, but you’re not quite sure what it means. All Temp, the experts in air conditioning repair Kissimmee, can help you make sense of whatever strange sound your unit is making. 

Cooling System on Roof


If your commercial unit sounds like a bumblebee, it could be an indicator of an electrical issue with the condenser fan motor, relay switch, or wiring. If you hear this noise, shut off your air conditioner and contact a professional immediately. 


A bubbling or gurgling noise typically means that the drain line is either cracked or clogged. In this case, turn off the air conditioner, and check the drain line for any clogs.  


While a single click when your commercial unit turns on is normal, constant clicking can indicate that something is wrong. Clicking can indicate one of several issues:

  • If your machine is clicking continuously but won’t turn on, there could be an electrical issue.
  • If the clicking noise is coming from outside your home, there could be an issue with the compressor.
  • If the clicking noise starts slow and gets faster, there could be an obstruction in the unit causing damage to the blower fan. 

Side of building showing vents


Banging or rattling typically indicates that something has come loose in your commercial HVAC system. This could be anything from a crankshaft to a connecting rod. Banging can also be a sign that your system’s compressor is worn off. If you hear banging or rattling, it’s best to turn off the unit to prevent any additional damage. 


When there’s a refrigerant leak somewhere in your system, it can start whistling. Refrigerant leaks should always be handled by a professional.

Great! Now you know what that strange sound coming from your commercial HVAC unit means, but where do you go from here? The best thing to do is to call in an air conditioning repair Kissimmee professional. At All Temp, we offer 24/7 emergency repairs. Just give us a call at (813) 630-9400 to speak with a professional.

Posted in AC Maintenance In Kissimmee