Central Vacuums 101: Frequently Asked Questions

Nov 18, 2019

Central Vacuums 101: Frequently Asked Questions

Central Vacuums 101: Frequently Asked Questions

Is your central vacuum acting up? If it’s making weird noise, or just doesn’t have enough suction, this video is for you. Andrew goes over many common problems or issues you might run into when dealing with a central vacuum.

Central vacuum systems are a good investment, but like all investments, they require routine maintenance. No matter what make or model vacuum you have, these tips will work for you!

Important Safety Tips

  • Always make sure your machine is unplugged and the power button is turned off, before servicing your vacuum.
  • Always make sure your hands are dry and free from moisture before servicing your machine.
  • Be sure to wear gloves when servicing your machine to prevent any cuts or scrapes.
  • If you are uncomfortable working on your vacuum, please don’t hesitate to contact us at service@greatvacs.com and we can help you through the process or you can send it into us to fix it for you. 


The Parts of a Central Vacuum Unit

You will notice four ports on the outside of a central vacuum unit. 

All of the ports on the bottom are for suction. The piping from your home will go into either the left or right bottom ports. Most homes only use one, so we will use that set up for our demonstration.

Your piping will hook up to one side and the other will have a length of PVC pipe with a cap on the end. A common problem we’ve seen is that homeowners hook up their pipe correctly on one side and leave the other side open, with no cap. When this happens the suction will go through the open port and you won’t have suction in the rest of your house.

The port on the front has suction, but you will also notice it has a lid with a seal. This needs to be closed for the central vacuum to have suction in the rest of your house. The purpose of this port is so you can attach the hose and vacuum the room where the central vacuum is located – like your garage or basement.

The port on the top is the exhaust port. Our units come with the exhaust muffler you see hooked up here. When the muffler is installed it will quiet the machine down while it’s running. Some people buy additional PVC piping and route the exhaust to the outside of the house. This blows the hot air outside and also further decreases the noise.

How a Central Vacuum Works

The central vacuum unit is usually installed on the wall of the garage. There will be piping that runs throughout the entire house and these pipes will end in hose connectors. The hose connection for our demonstration is right at the end of the suction pipe.

Your hose will plug into the wall outlet. Many central vacuum owners don’t realize that the wall outlet actually has wires that run all the way back to the central vacuum unit through the walls. These wires tell the central vacuum unit to turn on.

Each hose has two metal bands at the end that plugs in.

If you look inside the wall outlet you’ll see two brass tabs.

These brass tabs need to contact the metal bands of the hose for the unit to work.

There are two styles of hose. The first is “direct connect,” where you’ll see two prongs that stick out at the end. These prongs will plug into the port on the wall outlet when you plug the hose in.

The other style is “pigtail.” This style actually has a cord that comes from the hose and needs to be plugged into your standard 120V wall outlet.

All of our central vacuum units work with either hose style.

How Do Central Vacuum Wall Outlets Work?

As you can see in our demonstration, there is a wire that runs from the wall outlet to the unit. This wire send a signal when the hose is plugged to let the central vac unit know when to turn on. This means the vacuum doesn’t need to run constantly and you don’t need to go out to your garage to turn it on every time you want to vacuum!

If you were to plug your hose in sideways, both brass tabs would be touching the same metal tab. If this happens it will immediately tell the unit to turn on.

If your hose is turned off and you plug it in correctly the unit won’t turn on until you flip the switch.

Troubleshooting a Central Vacuum

Sometimes people buy a power nozzle and hose kit, go to use it, and then notice there’s no suction. The suction will not come from the power nozzle, wand, or hose. It will only come from the central vacuum unit. 

If you’re noticing that it’s not picking up as well as it used to, or as well as you think it should, you’ll want to check the suction at the unit itself.

First, make sure you hose is unplugged from all your wall outlets.

Then go out to the unit and find the on-off switch on the side. Flip it to on and the vacuum should turn on.

Once it’s on, go throughout your house and find all of the wall outlets. While the vacuum is running open each outlet and test the suction with your hand. If you’re having trouble even opening the flap you probably have adequate suction.

If you check the outlet and it doesn’t seem to have much suction, visually inspect it for signs of a clog. Check any piping you can access for clogs.

If there doesn’t appear to be a clog, you’ll want to check the tank on the bottom of the unit. Dump the dirt bin out and clean it. While you’re checking the dirt bin, go ahead and check that all of the filters are clean as well.

If the vacuum has good suction and everything is clean, you can move on to the hose. Make sure the flip the power switch on the central vac unit to off! This way it won’t just be running by itself without direction from the hose. 

When you plug the hose in make sure that the central vacuum unit turns on and that the power nozzle turns on. When you turn the hose on it should turn both of those parts on.

Now plug your hose in. In this example we show the pigtail style hose that needs to be plugged into the wall outlet. Depending on the style of hose, make sure it is plugged in correctly.

When you flip your hose switch to the #1 setting, it should just turn the central vacuum unit on. You should hear the suction turn on at the wall outlet when you do this. You can also go out to where the central vac unit is and make sure it’s on.

If you turn the hose to the #2 setting, both the power nozzle and the central vacuum unit should turn on. Some power heads have their own additional on-off switch, so after you turn the hose on check that the power head itself doesn’t need turned on!

Some power heads, like the one in our demonstration, need to have the pivot released for the power nozzle to turn on. If you were to turn the hose on with the pivot still locked, the power nozzle won’t turn on.

Now, if the power nozzle and the central vacuum unit are both turning on, but you STILL don’t have suction you’ll need to check the suction on your hose. Turn everything on, disconnect your hose, and check the suction at the end with your hand. If there’s poor suction there is likely a clog in the hose itself. You could try straightening a wire coat hanger and carefully insert it to dislodge any clogs. A broomstick also works to get at least a few feet into the hose.

One other trick you can try is inserting the end of the hose into the front suction nozzle of the central vac unit and try to suction the clog back out.

Two more places to check for clogs, if the hose is clear, include the main electrical wand and the power nozzle.

Disconnect the wand and you should easily be able to look through it. If you see light there is no clog and you can move in. If you see a clog you can use a coat hanger or broomstick and push it out.


If the wand is fine you can look down into the pivot of the power nozzle to check for a clog. You can also look behind the brush roll. If there is a clog you will typically see debris lodged there. If you see a clog in the pivot head you can try sticking the hose directly in to attempt to suck it out, or use a coat hanger.

Need a central vac? Check out the Prolux CV12000 featured in the video here!

Need to clean the filters on your central vacuum? We have a video for that!

If you need any parts, supplies or have any other questions, email us at service@greatvacs.com or leave a comment! You can also head on over to our YouTube channel to see more educational videos on all of our products.