Preparing for Your Big Day

Posted on: 17 December 2020

Your furnace's blower isn't a particularly mysterious device, and it does what you'd expect: it blows warm air away from the heat exchanger and distributes it throughout your home. Without a functional blower, heated air couldn't move through your ducts, and you'd spend your winter nights shivering under a blanket.

You don't usually have to do much to keep your blower operational, but it's a good idea to recognize where problems might crop up. In many cases, you can spot failures early and repair them before your home loses its heat. Below are three common failure points on many blowers and the symptoms that can potentially mean that trouble is brewing.

1. Fan Belt Failure

Furnace blowers broadly fit into two categories: direct-drive and belt-driven. A direct-drive fan integrates the blower wheel and motor into a single unit, while belt-driven blowers use a belt to transfer mechanical force from the motor to the fan blades. Belt-driven fans tend to be cheaper and quieter, so they are a popular option on many systems.

Fan belt tightening and replacement are both critical maintenance steps. Regular usage can cause the belt to slacken and wear, ultimately allowing it to slip. Slipping belts produce a telltale screech, just like a worn belt on a car. When you hear this noise, it's a good idea to replace the belt before it snaps and prevents your blower from working at all.

2. Bearing Failure

Like any electric motor, your blower relies on bearings to smoothly turn the rotor inside the stator. Bearings aren't complicated components, and they will typically last for as long as they have proper lubrication. Some furnaces require regular lubrication as part of routine maintenance, but the bearing oil should usually outlast the motor itself.

Unfortunately, other failures (such as overheating) can ruin the lubricating properties of the oil. When this occurs, you'll usually hear a constant whining noise that can eventually progress into a metallic grinding. The motor will ultimately seize, and you'll lose all airflow from your vents. In most cases, you must replace the motor to repair a bearing failure.

3. Overheating

It may be near your furnace, but your blower motor still has a maximum heat tolerance! Blower motors often overheat because of airflow restrictions, such as from a clogged filter. Anything that prevents the smooth flow of air ultimately causes the motor to work much harder, which can eventually cause it to overheat.

An overheating blower may produce a burning smell, or it may shut down unexpectedly. If you can find and correct the underlying cause, you may be able to save the motor. Leaving the problem unaddressed for long enough will wear down the motor's lubricating oil and damage its internal components. As a result, fixing this problem early enough can potentially save you hundreds of dollars.

If you experience any of these issues, contact furnace repair services.