Broken Belt? Why does it happen?

Certainly one of the most common cause of vacuum breakdown, the broken belt is has been the bane of vacuum cleaners since the first vacuum with a “beater bar” or agitator was made.

Often mistakenly called a fan belt, the agitator belt of your vacuum doesn’t cause a fan to spin, rather it makes a roller with rows of brushes (or brush strips) spin. These brushes “beat” or agitate the carpet surface, causing dust particles in the carpet fibres to become instantly airborne. Then these dust particles are immediately sucked up into the vacuum cleaner.

1. Overloading is the Culprit

The vacuum belt is looped around this brush roller and is driven to spin by a shaft extending from a motor. A vacuum belt is a little bit like the mechanical version of an electric fuse. When a circuit is overloaded, the fuse will blow. Likewise, when the brush roller of your vacuum is overloaded the belt will “burn” or break. Often the result is a strong smell of burnt rubber, and sometimes even a cloud of black smoke!

People have often told me that they threw out their old vacuum because it “blew up” when if they knew a little more they would have realized that the problem could be remedied with a part that only cost a few dollars.

2. Something Caught in the Roller

So why does a belt break anyways? Well there are several possibilities. First of all, the most common situation is something like this. Suppose you are vacuuming your home and letting your mind wander, and boom! Your belt breaks. It looks like you tried to vacuum your shoe, or a toy, or even worse the cord of your vacuum cleaner! The beater bar has seized up but the motor is still spinning. The shaft of the motor now heats up as it spins hundreds of time each second against a jammed belt. Within a second or two, the belt has melted at the point where it contacts the shaft and it’s all over. You need a new belt.

3. Height Adjustment Set Too Low

The second possibility is also related to heat and friction. It is the problem of setting the brush roller too low for the carpet surface. This is a big one, especially with the Hoover Windtunnel models. In these instances, you’ll have a nice thick carpet and you want to really get it nice and clean. So you set the height adjustment to the very lowest level. What happens here? The brush is now working too hard against the carpet and starts to spin more slowly. Meanwhile the shaft of the motor is still spinning at full speed. Soon the shaft starts to heat up but instead of the belt breaking, the slow rise in temperature cause it heat up and stretch. As the belt stretches, it starts to slip and eventually it just slips on one spot and the belt burns through. When this happens, you go to your neighborhood vacuum store and get into an argument with the clerk because he is trying to sell you a belt that is half the size of the one that broke. Of course the store clerk is selling you the right belt because your belt has stretched to twice the size before it broke.

4. Using the Wrong Belt or a Low Quailty Belt

A third a common reason for broken belts is that you are using the wrong one or one you bought at a dollar store. These belts usually look like they snapped not like they melted. Make sure you get the right belt by talking to someone who knows what they are talking about and avoid buying a vacuum belt anywhere they don’t fix vacuums. You might save three dollars but you’ll still have a problem.

5. Hidden Roller Damage

Finally, a more complicated problem. There may be something wrong with the brush roller of your vacuum. Brush rollers wear out, melt, the bearings break down, and suffer all kinds of abuse. The result is that they don’t spin properly or freely and this can result in the situation of a belt burning. This is a little more serious an usually will require you to leave your vacuum with a repair person for a couple of days. But even then, this kind of repair is almost always a cost effective maintenance type of procedure.