It is common for your HVAC system to make some noise. After all, they are quickly moving large amounts of air through your home, heating or cooling it to combat the natural temperatures of the season. Normal sounds include a low hum or a whoosh sound as the HVAC kicks in. But what if your HVAC system suddenly becomes unexpectedly loud or makes unusual noises? When should you start to worry about your HVAC system? To troubleshoot strange HVAC noises here we look at some of the most common sounds you’ll hear from your HVAC system, and what they mean.
1. Hissing Sound
A hissing sound from your HVAC system usually means that air is escaping from the system. If you listen closely and find that the noise comes from the walls, then the ducts may be leaking. If air is escaping your ducts into your walls, you’re wasting the heating and cooling power of your HVAC in the wall space of your home and not feeling the benefits in your living space.
If the ducts of your home need to be repaired, then you will need an HVAC technician to do the job. This is not a DIY task. In contrast, if the hissing noise is coming from the air vents, it could be because the air filter is not set right in the machine. In this case, you can usually correct the issue yourself by readjusting the air filter.
2. Clicking Sounds
Clicking is normal when your HVAC system is starting up, but ongoing clicking could be a sign of a failing control or an issue with the thermostat. Get the unusual and ongoing clicking checked out by your HVAC technician as soon as possible. It is critical as there are many electrical parts in your HVAC system that could be to blame for clicking sounds.
3. Rattling Sounds
A loud rattling noise in your HVAC system could mean multiple things. If the rattle is in the outdoor unit, it could indicate debris such as small twigs or rocks that have gotten inside. To correct this, you will need to turn off the system including its power supply. Then, you can open the unit and remove the debris. If there seems to be damage to the interior, then you should call an HVAC technician.
If the rattling noise seems to be inside your furnace or other parts in the interior of your home, then the problem is often more complicated to find and resolve. Rattling can be the result of any number of electrical or mechanical parts failing or coming loose. In this case, you will need to consult with an HVAC expert right away, as they will know how to check out the system and repair the problem.
4. Squealing Sounds
Squealing often results from outdoor fan motors or indoor blower motors that are going bad. However, squealing on startup can be a normal sound for some systems. If the sound is more of a high-pitched scream, then turn your system off and call a professional HVAC technician right away as this could indicate a refrigerant leak. Refrigerant leaks not only damage your HVAC but can threaten your family’s health as well.
5. Clanking Sounds
A clanking sound in the HVAC system could indicate a severe problem. Often a clanking sound means loose parts, such as loose blades, a blower motor fan, or pipes. While it might not seem like a big deal, loose parts left unaddressed can cause further costly damage to the system. If you notice loud clanking noises shut off your system and contact an HVAC professional right away. They can evaluate the system, locate the loose parts, and correct the problem before it worsens.
Unusual HVAC system sounds can be not only annoying, but also a warning that something is wrong. Any new and strange noise from your HVAC system should be inspected by a qualified HVAC professional. With their tools and experience your HVAC technician can diagnose and correct issues, restoring your HVAC system to prime working order and prevent further damage.