Why is my vent clicking

Strange Vent Noises

You are probably chilling on your sofa watching TV or reading a book when you hear popping noises. It can be worrisome or even somewhat scary right? Don’t worry so much. It could be due to noisy air ducts in your HVAC system. Such HVAC noises can make you wonder; why is your vent clicking?

Read on for a list of top tips on how to reduce or even stop HVAC noises completely. In addition, this article will discuss some causes of popping noises, weird HVAC noises, and reasons to call an HVAC professional.

Popping Noises In Air Ducts

Nearly all HVAC systems tend to make some noise when switched on. However, when you turn on your cooling or heating system and hear air duct popping noises, the HVAC unit may be faulty.

Similarly, you could hear banging noises that make you think you need furnace repairs or that your source heat pumps are broken. You may even worry that there are some loose parts. Well, there is good news and, unfortunately, bad news.

The good news is that there’s probably no serious problem as you may have thought. However, the noises you hear imply that your ductwork probably has minor issues. Until you take care of those issues, you may continue hearing air duct popping noises.

Here are some common causes of such popping or banging noises.

Pressure difference between ducts

Differences in pressure between supply and return ducts can cause loud noises in air ducts. Sometimes, pressure differences make the walls of your air ducts move in and out. As a result, it may emit rumbling popping sounds. This is referred to as “oil canning.”

Thin sheet metal ducts

If the sheet metal ducts installed in your home are cheap, thin, and undersized, they are not ideal for use as duct material. Sections in the metal are more likely to pop inward or outward when pressured.

Wrong size of ductwork

Unfortunately, some HVAC companies only offer cheap sheet metal ducts. They may not even install inappropriately sized ductwork. So, your HVAC system may end up having undersized ducts. That is to say, the ducts may be too small for a large amount of air coming through. If at the same time, the metals are thin and flimsy, you are more likely to hear a pop and bang when you turn the system on.

Temperature related expansion and contraction

Changes in temperature can cause expansion and contraction in air ducts. In turn, this leads to furnace popping noises. So, you may specifically hear banging and popping noises upon turning on the furnace. Usually, this can happen on frigid days when your furnace or source heat pumps are turned on after some idleness.

The sheet metal ducts are, as often is the case with many older homes, without insulation. Therefore, the furnace and the ductwork become cold. As a result, hot or warm air from the furnace causes the metal to expand quickly when it hits the cold ducts. Consequently, this rapid expansion of the cold metal leads to air ducts generating popping sounds.

Typically, if there is a creaking sound, it may mean the air ducts are expanding near wood.

Steps To Reduce HVAC Noises

Take the following steps to reduce loud HVAC system noises:

Step One: Clean, seal, and insulate your ducts

If you have insulated your ducts, you would know how much it costs to have such a system replaced entirely. Considering the kind of work it does, it is worth it. You can avoid a complete overhaul by duct cleaning, duct sealing, and duct insulating the system.

Also, note duct sealing comes before duct insulation. Sealing the ducts plugs any air leak that overworks your HVAC system, causing it to circulate unclean air.

This solution for heating duct popping noises works by reducing pressure differences. More so, it cushions the effects of expansion and contraction of metal ducts. Meanwhile, the more insulated your ducts are, the more you make your HVAC units more energy-efficient.

However, the duct sealing process is not as simple as using duct tape. It is better to call an HVAC expert for duct cleaning, duct sealing, and duct insulation. They are knowledgeable about duct cleaning, sealing, and insulation solutions like aeroseal duct sealing, acoustic duct liners, and fibreglass insulation.

Step Two: Examine the dampers and actuator

Next, examine the dampers. You can check the supply area of your ductwork for it. They are either open or closed. Attempt to open them sequentially. This may reduce the popping and banging noises.

Likewise, you can adjust the actuator within the duct dampers to reduce duct sounds. If necessary, your duct technician can help you with this.

Step Three: Replace your air filter

A replaced air filter can act as a sort of air purifier. This is especially true if the airflow is clogged. Changing out the air filter can improve airflow. Quite significantly, to assure better HVAC system efficiency and improved indoor air quality, clean or replace your air filter after every 30-60 days.

Step Four: Check if you have circular vents

Check whether you have rectangular vents instead of circular vents. The tendency is for rectangular ducts to make more noise as they easily contract and expand. On the other hand, circular vents make less noise because their geometric shape offers greater resistance to contraction and expansion.

Step Five: Regular HVAC system maintenance

Preventive measures to avoid unnecessary HVAC noises should involve maintaining regular maintenance schedules. This will ensure your HVAC system is not too dirty or inefficient. Thus, you may schedule maintenance and repairs like furnace repairs and heating repairs for every fall. Meanwhile, an expert can do air conditioner repairs and maintenance each spring.

Step Six: Replace ducted HVAC systems

Ultimately, you may consider replacing noisy air ducts with ductless zoning options. For instance, ductless mini-split HVAC systems run quietly in the background.

There may be advantages to replacing ducts. First, new ducts are likely to be insulated as per modern codes requirements. Second, the HVAC contractor may seal the ducts as part of the installation process. Finally, the vents are likely to be more appropriately sized.

Preferably, if you are not sure of the steps to replace a ducted HVAC system, call an HVAC professional or HVAC technician. They can easily identify issues that specifically cause the clicking of your heating system.

Causes Of Weird HVAC Noises

In addition to maintaining your indoor air quality at the desired temperature, your HVAC system is supposed to run silently. But, when you start hearing HVAC noises, it is a sign that the system may have a problem.

Clicking

You may hear noise (clicking sounds) coming from your air conditioners and feel irritated by it. True, the sounds can be repetitive and annoying.

Components that may cause the clicking noises may include a faulty fan blade, relay switch, compressor, or motor. Other culprits could be controls, the capacitor, control board, or thermostat. You can invite a local air conditioner repair team to inspect and do needed replacements.

One method to get to the bottom of the problem is to check the area the noise is coming from. If the clicking sounds seem to be coming from outside your home, it could be a loose component in the outside compressor.

Banging

You may also hear loud banging noises when your air conditioners come on. Again, the culprit could be loose or broken non-essential components such as the crankshaft, piston pin, connecting rod, or indoor blower.

Buzzing

There could be many reasons for a buzzing air conditioner. These can include loose, faulty, or unbalanced components. Change the air filter to stop the buzzing, but if the noise continues, call in a professional.

Squealing

An indoor blower motor or, possibly, an outdoor fan may cause squealing noises. Other likely causes are a faulty blower wheel and housing.

Rattling

Again, loose or damaged parts can cause rattling noises in air conditioners. In addition, it could be because of debris in the HVAC unit.

Flapping

Likewise, leaves or twigs can lie directly in the path of the fan blade. It is often easy to remove these, which solves the problem.

Whistling

Loud whistling or screaming noises in your HVAC should concern you. Call an HVAC professional immediately. It may be due to refrigerant leaks which may be toxic.

Call An HVAC Professional

You are now informed about some common causes of popping and weird noises in HVAC systems and air ducts. Further, you also know possible answers to the “why is my vent clicking” question. However, this list is not exhaustive. A different thing could cause clicking or popping noises.

Thus, it is wise to call an HVAC technician or professional to examine your ductwork and check the air vents and the entire HVAC system. After all, they have the right tools and provide home energy solutions such as energy recovery ventilators. One thing is certain, at the end of it all, you will have some peace and quiet at home.

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