A steady low hum when your furnace works is normal and no cause for worry. However, banging, scraping, or whistling noises from your heating system are alarming symptoms you shouldn’t write off. If your furnace suddenly begins making strange sounds, it’s a good idea to call furnace repair services in Lebanon, CT.
Are you asking, “Why does my furnace whistle when it turns on?” Keep reading. We’ll look at several possible issues that may cause your furnace to make that annoying sound.
Should You Worry About a Whistling Furnace?
Your HVAC system keeps your home comfortable and filters indoor air. Research has shown that HVAC systems can reduce airborne contaminants and improve indoor air quality. That’s why any potential problem with your furnace can affect both your comfort and your health.
A whistling noise from your furnace means something prevents air from flowing smoothly through your heating system. Possible causes include duct leaks, vent blockages, blower motor issues, and various other problems.
If you aren’t an HVAC professional, you likely won’t be able to diagnose and fix the issue yourself. Call a technician sooner rather than later, before the problem gets even more serious and expensive to repair.
Possible Reasons for Whistling Sounds From Your Furnace
If your furnace is making strange whistling noises, one of the following may be the reason.
1. Clogged Air Filter
Dirt, dust, pet dander, and other airborne particles all lodge in your air filter. With time, the filter becomes clogged, which may create an airflow restriction.
Luckily, dirty filters are easy enough to replace. Depending on their type, filters may need replacement every 1-3 months to once a year. Replacing your air filter is one basic HVAC maintenance task you can usually perform yourself.
2. Duct Blockage
Like air filters, ducts can likewise accumulate dust and debris over time. Sometimes, a duct becomes so clogged it restricts airflow and causes a whistling noise whenever your furnace is working. Professional duct cleaning can remove any obstructions and layers of dirt from your ductwork.
3. Blocked Vents
When something obstructs a vent, it restricts the airflow and increases air pressure in the ducts. The air moves faster, creating turbulence and vibrations, which explains the whistling you hear. Moreover, imbalanced air pressure strains the blower motor, which may also vibrate and whistle.
Thus, if you’re asking, “Why does my furnace whistle when it turns on?” check your supply and return vents to make sure that nothing blocks airflow. Sometimes, something as simple as cleaning the vents could get rid of whistling while your furnace works.
4. Blower Motor and Blower Wheel Issues
When a blower motor isn’t working properly, it will vibrate excessively. These vibrations may create the annoying high-pitched whistling you hear. You may also notice that your energy bills are growing as your furnace struggles to keep up. Your only viable option in this case would be replacing the blower motor.
Sometimes, the culprit is the blower wheel that propels warm air throughout your ductwork. If the blower wheel becomes loose, you may notice poor airflow and whistling noises when your furnace works. Fortunately, it’s easy enough to fix a blower wheel by tightening the screws that hold it in place.
5. Closed Doors
If you like to keep most of your inner doors closed, you may unknowingly interfere with your heating system’s work. Closed doors create a pressure difference between the central area and other rooms. The blower motor then works extra hard to push air through the tiny gaps around the door, which may cause a whistling sound.
Does this mean you must sacrifice privacy by keeping all doors open whenever your heating is on? Not necessarily. Slightly raised doors or ventilation grilles will let air pass even when doors are closed.
6. Not Enough Return Grilles
Air enters your furnace through return grilles in several locations around your home. When you don’t have enough return grilles, or when the grilles are too small, air pressure increases. You may then hear a whistling sound when your furnace is working.
7. Oversized HVAC System
Choosing the biggest HVAC system you can afford isn’t always the best move. An oversized system can push too much air through the ductwork, which may cause turbulence and whistling noises.
Even worse, this high air pressure may eventually cause gaps and leaks in the ductwork. Consult a professional if you aren’t sure what HVAC system size is right for your home.
How To Prevent Furnace Problems in Lebanon, CT
Now that you’ve learned several possible answers to “Why does my furnace whistle when it turns on?” you probably want to know how to prevent this issue.
Regular furnace maintenance will keep your heating system in good shape and catch any problems before they damage your furnace.
To help your furnace work properly, clean any debris from vents, make sure that furniture or other objects aren’t causing a ventilation blockage, and change dirty air filters as needed.
Apart from that, your heating system will need professional maintenance at least once a year. The coldest month in Lebanon, CT, is January, with average nighttime temperatures around 15°. Ideally, you’ll schedule an HVAC tune-up in the fall to ensure your furnace is ready for the cold season.
A professional tune-up includes testing and cleaning all furnace components, verifying that all the parts are working properly, and checking for any loose connections. We’ll also inspect your thermostat, recalibrate it if necessary, and replace air filters. We’ll finish by testing your heating system to confirm it’s running smoothly.
Furnace Issues in Lebanon, CT? Call SM Mechanical Services LLC
Strange noises from your furnace usually mean trouble. If you’re searching for an answer to “Why does my furnace whistle when it turns on,” get in touch with us at SM Mechanical Services LLC. As your experienced local HVAC contractors, we’re ready to diagnose and resolve any furnace hiccup. We offer furnace installation, repairs, and maintenance in Lebanon, CT, and surrounding areas.
Contact us to schedule a service call.