Making Sense Of 2 Strange Furnace Sounds

When all is well, the average furnace is capable of performing with a minimum of unwanted sounds. Yet when things start to go wrong, it is not uncommon to begin hearing all manner of strange sounds. If you would like to improve your HVAC diagnostic skills read on. This article will discuss the probable causes behind two of the most frequently encountered furnace noises.

Pops And Bangs

Strictly speaking, such sounds are probably not the result of furnace problems. It is actually your duct system that is giving rise to these startling and highly annoying sounds. The cause is so common and specific that is has its own name: oil canning. This term refers to the metal oil cans of yore, which had a tendency to buckle inward noisily as the oil was squeezed out.

The same thing happens here, with the changes of pressure and temperature within the ducts causing them to fold inward. The flexing metal thus gives rise to all manner of sounds. Fortunately, oil canning represents a problem that can be solved fairly easily. Simply locate the troublesome section of duct, loosen its attachment hardware, and slip a piece of felt padding between the duct and the framing element. This will help to absorb the sounds.

If the problem still persists, you may be able to alleviate it by opening up more of the registers inside your house. This will help to equalize the pressure inside the duct system, making oil canning less likely to occur. Should the problem continue, contact a furnace technician to help bolster your duct system through the installation of so-called brace drops. These are considered the most sophisticated means of quelling unwanted oil canning.

Shrill Squealing

In virtually every case, a high pitched squealing noise is related to your furnace's blower system. The most common cause is a belt that has worn itself thin and frayed. The sound is often the result of the belt encountering minor slippage as it transfers energy from motor to fan blades.

In other cases, the sound is tied not to the belt but to the fan assembly itself. Generally this indicates either motor or fan bearings that have become worn out and lost their lubricant. Here the squealing results from the friction between the bearings and their housing. Should the problem be allowed to persist, the squealing may be accompanied by grinding sounds as the bearings begin to break apart. Eventually the blower system will cease to function at all. For that reason, it is important to have the problem addressed as soon as possible.

For more information, talk to a professional like Boyers  R S Heating &  Air Conditioning Inc.