Motors and Maintenance for Silent Master Central Vac
All Products for Silent Master
Only hear a "click" when trying to start the system? Does it shut off and start back up in a few minutes? These are common signs of a dead motor which only leaves two options. Replace the motor or the replace unit. If you liked the amount of suction it originally had, then replace the motor. If you'd like stronger suction or if you'd like a cleaner disposal system consider a different unit or alternative brand.

How is a central vacuum maintained? Generally, the only thing required is emptying the main unit. Beyond that there are some upkeep and preventative options given below.
Replacement Chart for Silent Master Vacuum Motors, Filtration, & More
Model # Replacement Motor Filtration and Parts

S1
110-120 volt
Buy Now / Details & Instructions
116764		 Bag #721H-5 or
Closed Bag Option
Relay #242 Transformer #232

S2
110-120 volt		 116336 MotorPrice / Details /
Instructions
(takes 2 motors)
119413

For more power use 2 116336 motors. They are a bit louder too. 		Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #235M
Transformer #232

S2
220-240 volt		 Buy Now / Details & Instructions
(takes 2 motors)
116296		 Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #236M
Transformer #231

S3
110-120 volt
Buy Now / Details & Instructions
(takes 2 motors)
116764		 Bag #721H-5 or
Closed Bag Option
Relay #242
Transformer #232

S3
220-240 volt


Buy Now / Details & Instructions
(takes 2 motors)
116945

 Bag #721H-5 or
Closed Bag Option
Relay #242
Transformer #231L

S4
110-120 volt
Buy Now / Details & Instructions
117939		 Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #235S
Transformer #232

S4
220-240 volt
Buy Now / Details & Instructions
117944		 Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #236S
Transformer #231

S44
110-120 volt
Buy Now / Details & Instructions
119956		 Bag #721H-5 or
Closed Bag Option
Circuit Board
#235L
S5
110-120 volt
Buy Now / Details & Instructions
(takes 2 motors)
117939		 Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #235L
Transformer #232

S5
220-240 volt
Buy Now / Details & Instructions
(takes 2 motors)
117944		 Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #236L
Transformer #231L

SP2
110-120 volt		 Buy Now / Details & Instructions
117478		 Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #235S
Transformer #232

SP2
220-240 volt		 Buy Now / Details & Instructions
117572		 Bag #721H-5 or
Closed Bag Option
Relay #242
Transformer #231

SP22
110-120 volt		 Buy Now / Details & Instructions
(takes 2 motors)
117478		 Bag #721H-5 or
Closed Bag Option
Relay #242
Transformer #232

SP22
220-240 volt		 Buy Now / Details & Instructions
(takes 2 motors)
117572		 Bag #721H-5 or
Closed Bag Option
Relay #242
Transformer #231L

SP3
110-120 volt		 Buy Now / Details & Instructions
117500 (replaces 119389)		 Bag #721H-5 or
Closed Bag Option
Relay #242

or Circuit Board #235S
Transformer #232

SP3
220-240 volt		 Buy Now / Details & Instructions
117502		 Bag #721H-5 or
Closed Bag Option
Relay #242
Transformer #231

S1 Foreign
220-240 volt
Buy Now / Details & Instructions
116296		 Bag #720H-5 or
Closed Bag Option
Relay #242

or Circuit Board #236S
Transformer #231
Basic Maintenance for Silent Master Vacuum

Filtration Maintenance
Silent Master Vacuum Motor ReplacementMuch like a regular portable vacuum, the basic maintenance of a Silent Master Central Vacuum System is changing the bag in the main unit. To do this, remove the top of the unit, remove the black gasket, if installed, then lift the paper bag and support bag out together, and place a paper bag into the trash can. Put a new paper filter into the support filter, wrapping the elastic over the edges. Set the filter into the vacuum putting it below the necks of the intakes. Some vacuums have a closed bag that slips off an elbow and a new bag is simply slid back on. Below the support filter is a mesh filter that keeps large debris out of the motors if there was an accident with the main filter. The Silent Master Owner's Manual is available here and please note that over the years the look of the vacuum has changed.

Motor and Vacuum Maintenance
There is nothing to lube or oil in or on the central vacuum system, including the Silent Master motor, Silent Master vacuum motor unit, or Silent Master vacuum cleaner. For the indoor vacuum brush, the fibers that get wrapped around the brush roll of the vacuum cleaner head should be cut out and removed on a regular basis.

Pipe and Hose Maintenance
We recommend cleaning out the hose and piping system at least once per year. The best way to do that is with Tornado Central Vacuum Maintenance Cloths. They do a couple of things. First, they push through the pipes, bringing along stalled out debris. Second, they deodorize the hose, pipes, and unit. Some amazing results can come from this product. The vacuum hose will last longer if it is stored on a hanger, always being detached from the vacuum after each use. See if any of these Storage Items can help your situation (scroll to the bottom of the Accessory Page).

Email Reminders to Empty Vacuum
Sign up for the Free Quarterly Email Reminders to dispose of your central vacuum debris. Let the trash build up can reduce suction, making the unit run hotter and clean less efficiently.

Replacement Motors and Parts for Silent Master Vacuums

Troubleshooting
Self diagnose your system using this Interactive Troubleshooting Guide and Solutions.

Motor Replacement
Contact a local dealer for service, or consider doing it yourself. Motors on the Silent Master vacuum have a few fasteners and wires that need to be unattached, the reattached on the new motor. It should take less than one hour. First, turn off the circuit breaker or unplug the central vacuum unit. Then, access the motor by releasing the outer housing. Use the chart to find the right replacement motor for your Silent Master motor model. A motor may have many numbers on it but typically the real motor number starts with 11. Here are detailed Silent Master Motor Replacement Instructions.

Circuit Board, Relay, Transformer, MiniBreaker
Prior to 8/2004, Silent Master units used a separate transformer, relay, and minibreaker. Since then, a circuit board is installed which houses all these electronics. The most common circuit board replacement for single motor Silent Master vacuums is the Vacuum Motor Circuit Board for Single Motor Units 110 Volt. For other models with different voltage and two motors the replacement circuit boards are here. These robust boards are made by an industry supplier. Here are relay and transformer wiring diagrams for past models:

Motor Carbon Brush
The Silent Master motor has two carbon brushes that wear down and can be replaced before they damage the motor. However, the Silent Master motor may go bad for other reasons while the carbon brushes remain fine. Silent Master motor brushes can be checked every few years and replaced if the 3/4-inch-long solid carbon is worn down. Definitely replace if one or both are down to 3/16 inch. Type the motor replacement number (not model number) in the search box and the motor brushes will come up along with instructions.
 
Note: Silent Master Vacuum is a registered trademark of M.D. Manufacturing, Inc.
Need more help? Try our extensive and helpful Silent Master Vacuum Questions and Answers or give us a call at 1-800-997-2278 M-Th 7 a.m. to 5 p.m. Pacific Standard Time.