As a leading Houston heating and AC repair company, we’re often asked by clients with an older furnace about noise-related issues. It’s not uncommon for a furnace to make noise as it ages. The unit may become louder than normal or make popping, booming, screeching, squealing, and other ominous sounds. Furnace noise isn’t always a cause for alarm, but may sometimes mean heating services like furnace repair, replacement, or an HVAC tune-up are needed.
While newer models are usually quiet, with any unit, listen to your furnace carefully. The sounds it makes may indicate it needs service. Some noises you may hear include:
The occasional pop, ping, or bang is nothing to be worried about. These occur because the heating process causes ductwork to expand and contract. However, when these sounds become louder and more frequent, calling an HVAC technician is a good idea. A dirty burner may be causing delayed ignition. If the problem persists, it can lead to a cracked heat exchanger, which may require heater replacement.
Booming noises can also be caused by the expansion and contraction of air ducts or by delayed ignition. That’s because a small gas explosion occurs when excess amounts of gas build up in the combustion chamber. The possible causes include a clogged burner, dirt buildup, or low gas pressure. Regular furnace maintenance can avoid these issues and prevent or reduce any booming sounds you hear.
You may hear rumbling and roaring from your furnace if it’s burning oils that weren’t consumed during the last cycle. If the rumbling is unusually loud, call a technician. There could be a problem with the burners, blower motor, or flame sensor, which may warrant a minor repair.
Clicking sounds are often heard during ignition. However, if you hear a continuous clicking sound and your furnace doesn’t ignite, or the blower quickly turns off after starting, the flame sensor may be faulty, which can lead to a carbon monoxide leak.
The blower motor is typically the source of screeching and squealing. When you hear it at an increasing intensity, motor bearings are drying out. If that’s the case, lubricating them should help alleviate the problem. For the best results, use a mineral or synthetic oil lubricant. A worn or broken belt can trigger the noise as well, so consult a furnace technician in Houston to determine the appropriate heating and cooling repair before the unit breaks down.
A blower motor issue may also cause whistling noises. The cause is likely low airflow because the motor is struggling to draw in enough air. You can try opening all the vents or changing the air filter. If these steps don’t help, call a contractor for an evaluation and possible furnace repair.
If you hear what sounds like metal rubbing against metal, the blower wheel may be loose, causing it to scrape against the blower casing. The wheel may also be broken. If scraping noises start, turn off the furnace and call a technician. Letting it continue to run may cause additional damage.
A vibrating furnace can be quite irritating. It may have a loose blower fan or motor. Or, dirt, debris, or an object may have jammed inside the blower. Loose panels on the furnace or air handler can also make vibrating sounds, as can ducts that have become disconnected. Therefore, if you hear vibrating, call a technician to tighten any loose parts, check for damage, and perform furnace repair as needed.
Your furnace has metal components that heat up when it’s on. Once the unit shuts off, these cool down and may make a crackling sound as they do. While this usually isn’t a concern, all parts should be checked during furnace maintenance or an HVAC tune-up. Your technician can spot repair issues or signs of wear and tear to fix.
If your furnace is wheezing (or making a whooshing sound), the filter may be dirty. Air is trying to force its way through. Replacing the filter should resolve the noise by restoring airflow and catching any suspended particles. If not, call for help.
When to Call a Technician
If your heater is louder than normal or making unusual sounds, call Village Plumbing & Air right away. We’ll send a technician quickly to evaluate and fix your furnace or, if necessary, perform heater replacement. If you hear any of the noises above or the unit is blowing cool air, frequently cycling, or you smell gas, don’t hesitate to call (these issues can often be addressed with a furnace repair or adjustment).