Why Your Furnace is Making a Fuss

A clanking furnace can certainly make for a fitful night of sleep, but it also indicates your HVAC system needs extra attention. Think of these sounds like symptoms. If you have a fever, you know you’re fighting off an illness; in the same way, these weird noises alert you to problems with your furnace’s inner workings.

HVAC issues are especially likely to surface in fall and winter in Houston. If you have a heat pump, it’s likely not used to working in reverse to heat your home, making previously unnoticed issues more likely to surface during our brief heating season. The same can be said for your furnace if you have one.

Fortunately for you, a seasoned professional can diagnose your HVAC system based on the noises your furnace or heat pump is making. Here are the most common sounds that indicate you have a furnace problem on your hands.

Squealing, Screeching and Chirping

If you hear a high-pitched squealing, screeching or chirping sound, the issue is likely related to your blower motor. The blower motor is the part of your furnace responsible for powering the fan that distributes the warm air throughout your house. An impaired blower motor means less heat in your home!

Three issues may be causing your blower motor to make a racket in this instance.

· No lubricant – Without lubricant, your blower motor is being subjected to unnecessary friction. Look for oil ports on the sides of your blower motor or blower shaft. If your system has them, put two or three drops of oil in each. It’s important you use furnace-specific oil, not all-purpose oil.

· Loose fan belt – The fan belt is located on the motor pulley. If there’s too much slack, you will need to restore tension by tightening the belt. The belt may also be worn enough to warrant replacing.

· Motor bearing issues – Bearings allow the motor to provide the force needed to power the furnace while reducing unwanted friction. You will need to replace any broken or worn bearings with new ones to restore functionality.

Clanking, Scraping and Thumping

If the noises are loud and persist when your furnace is on, not just when it starts up, there could be several potential causes.

· Loose or broken blower wheel – The blower wheel, which is spun by the blower motor, can loosen and move around, producing the loud metallic sound. This can cause more serious damage over time, so it is best to have it tightened right away. You’ll need a replacement if it’s damaged.

· Loose motor mount – Sometimes the motor mount itself will come loose, allowing parts to clatter and clang along the housing.

· Rattling or unbalanced parts – The whole blower assembly contains many parts and can become unaligned. A professional can assess which parts can be salvaged and which need replacing.

Banging on Startup

If you hear a banging noise that only happens when your furnace kicks on, it’s unlikely that it’s a loose mechanical part. More likely, it’s one of these two problems.

· Delayed ignition – A furnace is run by a chain of reactions. Based on the temperature picked up by your thermostat, a valve opens and lets natural gas into the combustion chamber. The pilot light or igniter then ignites the burner, and the heat from the subsequent reaction is used to warm your home.

Sometimes ignition doesn’t work right away, leading to gas buildup. When it finally ignites, the result is a mini explosion – the loud bang you hear – that could eventually damage your heat exchanger beyond repair. This delay could be caused by a dirty burner, faulty igniter, ineffective pilot light flame or improper gas pressure.

· Funky ductwork – If the bang doesn’t seem to be coming from the furnace itself, it’s probably a result of your ductwork expanding and popping out. Your ducts may be too small or rectangular, and might require replacement to alleviate the noise issue. The fix could also be as simple as opening more vents to relieve the pressure or double-checking the air filter is free of debris.

Other Sounds

Your furnace might make other sounds, such as humming, rumbling, rattling or clicking. If your furnace only makes a clicking or humming noise when it starts up, everything is likely functioning fine. However, while some of these noises are an easy fix, you never want to put you and your family at risk for something more serious, like a total loss of heat or carbon monoxide poisoning. It’s best to err on the side of caution and have a professional HVAC technician assess the state of your furnace.

Repair a Faulty Furnace with AirCon Service Company in Houston, TX

If you’re hearing any strange sounds coming from your heating system, our team at AirCon Service Company would like to help. Our experienced technicians have been serving the Houston area for almost 50 years now, and we’ve been recognized for our caring customer service with the Angie’s List Super Service Award for four years in a row, as well as the BBB Pinnacle Award.

AirCon Service Company can provide heating services for any furnace make and model, including repair and replacement. We also offer routine maintenance, tune-ups and safety inspections to prevent future furnace breakdowns. Contact us at (281) 823-8771 to schedule an appointment today!