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Modern Day Central Vacuum Parts - Maintenance

How is your Modern Day central vacuum maintained? Generally, the only thing required is emptying the debris and cleaning or changing the filtration. Beyond that, there are some upkeep and preventative options given below.

Basic Maintenance for Modern Day


Much like a regular portable vacuum, the basic maintenance of a Modern Day Central Vacuum System is changing the bag, or, in most cases, emptying the dirt receptacle on the main unit. To do this, follow the below steps for your filtration type:

+ Tru-Seal Filtration Bags

  1. Lift the lid off the vacuum unit and set aside. Detach Bag from Adapter(s). Slide the left and/or right connection(s) off the bag adapter(s). On the front utility valve connection, lift the plastic latch arm up to unlock the seal. Slide the connection off. For maximum dust control, attach the cap(s) to each connection seal.
  2. Remove Tru-Seal Microfilter Bag. Grab the top of the Microfilter Bag with two hands and slowly lift it up past the bag adapter(s). Set the bag in an appropriate waste bin. Remove the Support Bag and shake it out only if it contains visible dirt or dust. The Tru-Seal Support Bag is designed to be reused.

+ Open-Top Elastic and Single Connection Closed Bags

  1. Remove the lid from the unit, and turn the vacuum on manually. This will keep the dust completely out of the air. Use a dusting brush accessory to sweep down dust around the rim of the bag and in the necks. Some bags are open-top, others are closed.
  2. If present, remove a thick rubber gasket around the top of the open filter bag by pulling gently on its edge.
  3. To remove the filter bag, locate the pull tab (ribbon loop) located on the top edge of the filter bag. Pull up on the pull tab. Both the paper bag and the cloth support come out of the unit. The paper bag is fitted inside the cloth support.
  4. Remove the paper filter bag from the cloth support by pulling the elastic edge over the metal ring of the cloth bag. Discard the paper filter bag.
  5. Insert a new paper bag into the cloth support and stretch the paper bag elastic over the metal ring of the cloth bag. For closed bags simply remove and replace with new one.
  6. Replace the cloth/paper bag assembly inside the unit and press it into place.

    NOTE: Make certain the entire filter unit is below the utility valve and vacuum inlet necks and that the pull tab loop on the cloth bag is pointing up.

  7. Insert rubber bag gasket. Set it in place and push the remaining hump down into place.
  8. Turn off the vacuum and replace the lid.

Reminder Emails Sent to Empty Your Modern Day Vacuum

Sign up for Free Quarterly Email Reminders to remind you to dispose of your central vacuum debris. Operating your unit with a full filter can reduce suction, making the unit run hotter and clean less efficiently. Your email will not be used for any other purpose, or be sold or borrowed. We simply want to help you remember to keep your Modern Day Central Vacuum working at its top performance.

(The image shown does not reflect all types of central vacuum filtration.)

Click Here to Start Your Reminders.


How a Vacuum Motor Works

All Modern Day units used permanently sealed motors in their main collection unit. They require no lubrication or oiling. Routine maintenance for typical residential usage should include checking the motor brushes approximately every five years. While checking the motor brushes, make sure the center motor shaft is solid and has no play or wobble. If it does, the bearings are going out and the motor will need to be replaced. If the motor brushes are worn to 3/16 inch long, replace the motor brushes.

If the unit does not have any paper or cloth bag filtration, then a certain volume of debris may accumulate on the motor's internal fan blades. This is not easy to remove and any attempt to remove it has the high possibility of offsetting the balance of the fans. An imbalanced fan causes premature motor failure on the motor bearings.

Here are instructions for checking and replacing vacuum motor brushes. Motor brushes conduct electricity into the motor while touching the center shaft. Over time, they wear down. If they wear all the way down, they can damage the motor.

Click on the image above to understand how a vacuum motor works.

Motor Replacement

Modern Day Vacuum Motor Replacement Help

You have a couple of options when it comes time to replace the motor on your Modern Day Central Vacuum. Contact a local dealer for service, or consider doing it yourself. Motors on the Modern Day vacuum have a few fasteners and wires that need to be unattached, then reattached on the new motor. It should take less than one hour to change your motor(s). Here is a quick "how-to" change your motor:

  1. Use the Modern Day Motor Replacement Parts Chart to find the right replacement motor for your Modern Day model. When your new motor arrives, take some photos of your original motor so you remember how it was wired and secured.
  2. Turn off the circuit breaker or unplug the central vacuum unit.
  3. Access the motor by releasing the outer housing (usually a few screws around the perimeter). Remove the motor and unclip the motor wires from the components.

    Note: Your new motor may not have the correct wire ends. If that is the case, we recommend cutting the wires from the old motor and wire nutting the new motor wire to the old motor wire. Using the original wire with the correct end to attach to the components makes your job a lot simpler and the connections safe and secure.

Note that a motor may have many numbers on it, but typically the complete motor number starts with "11" followed by 4 more numbers and maybe a dash with two more numbers (e.g. 115334-00). Years ago, they didn't put the complete part number on the motor.

For more information, see our detailed Modern Day Motor Replacement Instructions.

Motor Brushes

Modern Day Motor Brush Help

The Modern Day motor has two carbon brushes in each motor that wear down but can be replaced before they damage the motor. Modern Day motor brushes should be checked every five years in typical residential applications and should be replaced if the 3/4 inch-long solid carbon "brush" is worn down to anywhere near 3/16 inch. Here are instructions for Checking and replacing vacuum motor brushes. Motor brushes conduct electricity into the motor while touching the center shaft. To find the replacement motor brush for your Modern Day Central Vacuum, type the motor replacement number (not brand model number) in the search box and the motor brush will come up in the search result; instructions are on the motor brush page.

Know that the Modern Day motor may go bad for other reasons, such as bad bearings or dust build-up in the motor (both are not repairable). If your motor brush doesn't show up under your original motor model number, replace the motor, not the motor brush.


Modern Day Circuit Board Replacement

In 2004 all MD Central Vacuums transitioned to an all-in-one control board. If your Modern Day Central Vacuum needs a new relay, transformer, mini breaker, or even a new control board or circuit board, use one of these powerful, durable, cost-saving central vacuum circuit boards. You save money, time, and headaches. The reality is, a central vacuum really only requires a motor and one circuit board. It is not terribly difficult to retrofit a circuit board. An electrician can do it in under an hour.

To find the circuit board you need, verify the number of motors in your unit and the amperage requirements. The most common board replacement for Modern Day Vacuums is the Vacuum Motor Circuit Board for Single Motor Units 110 Volt. For other voltages and motor configurations choose one of these Durable Generic Circuit Boards made by the industry leading manufacturer. Or, use your model number and the Motor Replacement Parts Chart for Modern Day to see our recommended circuit board. There are other Generic Circuit Boards for units with different voltage and multiple motors. Print and use the large photograph of the board as the wiring guide.

Older wiring diagrams for pre-board units:
Inlet & Pipe System Maintenance for Modern Day
Modern Day Inlet Help

Inlets can get worn out, lose contacts inside the hole, have a gasket or spring missing, and leak air. Parts are not available for central vacuum inlets; therefore, the entire inlet needs to be replaced. Good news is they are not expensive and it is not difficult to replace an inlet valve once you watch our How to Replace an Inlet Video for directions. New vacuum covers look fresh and function much better. New styles, colors, and designs are also available and are compatible. A trim cover is also available during checkout and is useful for covering the marks on the wall where the old inlet sat. Most inlets can be installed opening up or opening down. If you wish to have a different style or color, you can choose from a number inlet cover plates. Look for your inlet replacements here.

Modern Day Vacuum Pipe Maintenance Sheets

The pipes in your system should last for the lifetime of your home if properly installed. If black carbon dust has gathered on the exterior of the pipes through static electricity, it can removed with a damp, soapy cloth.

We recommend cleaning out the interior of the piping system at least once per year. The most effective method is with Free Flow Central Vacuum Maintenance Sheets. They do a couple of things. As the sheets are pulled through the pipes, they push along all kinds of items that sit in dead spots, as well as deodorize the hose, pipes, and unit. Some amazing things can be pushed out from your Modern Day Central Vacuum pipes, resulting in better suction. We have seen Match Box Cars, C02 cartridges, pencils, rocks, paper clips, and huge clumps of nasty debris.

Hose & Vacuum Head Maintenance for Modern Day
Modern Day Hose and Vacuum Head Help

Enjoy more years of maintenance free vacuuming by taking care of your equipment. The vacuum hose is an expensive part of the system but will last longer if it is stored on a hose hanger. Never store it attached to the vacuum wands, as it creates a stress fracture in the hose where it bends down from the wands. The best way to hang the hose is to create four or five loops on the floor before picking it up to be hung. It is not recommended to create more loops as this can cause more frustration trying to keep it on the hanger and unwinding it. Consider a Hose Cover to protect the hose and your baseboards and furniture. See if any of these Storage Items can help your situation. Consider hose hangers, wand hangers, hose straps and more. You can get everything off the floor for a more organized closet.

Your carpet brush also requires care. Take time to trim off long fibers and hair that have wrapped around the roller. The roller brush is a perfectly balanced part that spins incredibly fast. But when off balance, friction and vibration can create premature failure of the bearings and bushings. It is quite easy to check and clean your vacuum periodically.

Troubleshooting for Modern Day
Modern Day Vacuum Troubleshooting and Repair

Self diagnose your system using this Interactive Troubleshooting and Repair Solutions Guide for Modern Day Central Vac. We guide you through a simple, methodical deduction of tests and symptoms to find the problematic source of anything from:

We then offer a description of the problem and solutions to repair your Modern Day Central Vacuum. We also have 100s of local, independent dealers you can reach out to for help.

Visit the Troubleshooting and Repair Solutions Guide for Modern Day Central Vacuum