HVAC is the central part of everyone’s comfort that many take for granted. Now, we wouldn’t want something to happen to it, would we? Hence, it’s best to keep an ear out for something out of the ordinary. First of all, we are well acquainted with noises our HVAC makes, so it’s quite easy to recognize noises that appear out of the blue and lurk around. At times, these may not indicate anything serious. However, at times you may need to call out for an HVAC repair specialist as soon as possible.

HVAC Noises And Related Problems:

Hissing noise:

You wouldn’t find a rattlesnake in your HVAC unit when you hear such a sound; we can say that for sure. Nonetheless, what it can indicate may be bothersome. Generally, a hissing sound emanates from a refrigerant leak. However, where the sounds originate can tell you more about the problem.

If the sound comes from the A/C compressor, an internal leak might lead to high internal pressure. Disconnect the power and then call Crump A/C and heating. On the other hand, if it’s coming from the furnace, there might be an air duct leak and will require professional repair.

Squealing and Screeching:

This is a symptom of component failure. Such sounds may indicate motor issues or a bad motor belt. If the problem is with the motor belt, you may need to get it replaced. However, if you still choose to operate your HVAC unit on a bad belt, the belt might break. Then the motor will come to a screeching halt.

Other than that, the HVAC motor may start screeching due to a lack of lubrication, and friction starts getting the best of it. In such scenarios, lubrication is necessary, which can be a DIY project depending on your HVAC model.

Frequent Clicking:

You can hear a clicking sound when the HVAC unit starts. However, it dies down soon after, but at times the clicking sound may continue persistently. If that’s the case, it may indicate some sort of fault in the electronic control system, and the defective relay may cause it, or there might be a problem with the thermostat.


Is this common noise coming from the outside A/C unit? It may point out several issues. These issues include loose parts, imbalance in fan motor, loose fan blades, debris in either indoor or outdoor units, or there may be a refrigerant leak. In case of a refrigerant leak, you feel indoor cooling dwindle.

Banging, Thumping, and Rattling:

These sounds may originate from the furnace’s blower assembly or motor, which most likely means that something in there is loose. If you hear the banging sound getting louder, the loose piece has most likely broken off. Further using the unit will cause damage to the system, so shut it down and wait until the professionals arrive.


The best practice is to shut it down and wait for professionals whenever you hear anything unusual. Call Crump A/C and Heating at 281-533-9200 whenever you hear something unusual.

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