It’s Halloween season—you’re in your home and you hear a strange rattling, or perhaps a shrieking noise. It’s not quite trick-or-treating time so you can’t blame it on little kids at your doorstep. Could it be that your house is haunted?!
Okay, probably not. Is your heater on? That’s likely a more realistic explanation for the sounds you’re hearing.
But just because it’s a more reasonable explanation doesn’t mean it’s an acceptable explanation. Your heater shouldn’t be making strange or unfamiliar sounds, and if it is it definitely means something is amiss and needs repair. So what sounds, exactly, should you listen for? Read on!
A Loud Bang at Startup
This is one of the scariest noises you might hear coming from your heater—a loud banging sound from the furnace. This is particularly alarming if it’s a gas-powered system.
If this banging happens consistently, rather than when the furnace first starts up, it may have something to with the ductwork or sheet metal siding of your heater expanding and contracting. This can be the result of poor duct installation or inadequate furnace sizing. This is definitely something that needs to be checked on, but it’s even more concerning if this noise only happens during startup.
In this case, it might be something like a dirty burner. That doesn’t sound too ominous, but actually, when that dirt builds up too much it creates a sort of “mini explosion” when the burners ignite, since they’re insulated by all that dirt. This might not affect your home right now, but it rattles the heat exchanger, which can eventually crack and allow harmful gas fumes into your living space.
This can be the result of a lack of lubrication, or blower fan belt that’s worn out. This means it’s a fairly easy fix for our technicians—but that doesn’t mean you can ignore the sound. If you let this continue for too long, the fan can stop working, stopping your furnace from running when you need it the most. It’s better to fix the problem now than to wait for a sudden heater breakdown.
A common explanation for this type of noise is that the pilot flame is too low. Be sure to check the flame to see that it’s blue, instead of yellow or orange. If this isn’t the problem, then a rumbling sound can be attributed to a dangerous carbon monoxide leak, depending on the unit, so the best thing you can do is shut the system off and call for help.
Do you hear something that resembles the sound of metal on metal? This should never be ignored. Most likely, the motor mount has become loose from its casing—in other words, it sounds like exactly what it is, metal on metal.
This may not seem like a big deal, but if allows to go on it can definitely damage your heating system and make the system ineffective.