Sometime in the middle of a cold winter night, while you're snuggled warm in your bed, a screech screams out throughout the house and you pop out of bed like you've been visited by a legitimate banshee. Before you seek safety in the confines of your closet, along with your rattled nerves, you should know there is probably a logical explanation for what you are hearing. Sometimes, a furnace can make some pretty creepy, fear-inducing sounds, so you may not actually need that number you're trying to conjure up from memory for the local paranormal expert. Go ahead and swallow your fear, put down the baseball bat, and head to the furnace. Here's what you need to know about a squealing furnace. 

Turn the furnace off—quickly!

If you're in the middle of a furnace-screaming situation, your very first plan of action should be to cut the power to the unit as quickly as possible. There are a few things that could be causing this dreadful, horrid racket, and none of them are things that should be allowed to carry on any longer than necessary. When you cut the power, you will be disrupting the motor and any moving parts, so the noise should cease right away. 

Call a heating repair professional for advice. 

If you're lucky, this disastrous situation will not happen in the middle of the night, but if it does, hopefully, you have a 24-hour heating repair professional you can call in for some rapid assistance. In some cases, the professional may be able to lead you to the issue over the phone so you can make simple repairs on your own and head back to bed. They may ask you to look at something like the belt that turns the fan motor or the inside of the unit behind the access panel to see if you see any debris. Sometimes, a belt will slip out of place and generate the squealing noise, and this is a fix that most homeowners can do on their own. 

Prepare for a little downtime if you find debris inside the furnace. 

If the professional instructs you to check inside the furnace for debris, and you do see some, you are likely going to be facing repairs. In some cases, the squealing will radiate from the blower motor if the fan is warped or bent, and this can, unfortunately, lead to damage to the internal parts of the blower that will result in scattered debris.