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TroubleShooting Power Unit Issues Q&A

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116515-13 Motor Trips Breaker

Hello, I have an Electrolux 1590 Central Vac with a Lamb 6765-07 motor that is worn out. It still runs but the brushes have worn right down and grooved the armature. I ordered a new motor from a vacuum Dealer locally and he supplied me with a Lamb 116515-13 motor. When I install it and hook it up it keeps tripping my main breaker on my breaker box. This is the second motor he has supplied me because we assumed that the first was faulty but the second one is doing the same thing. It cuts in for a split second then trips the breaker. What is the deal ??? If I install my old motor back in the unit it starts up and works fine and does not trip the breaker. What do you think?


Your system requires a Lamb Ametek Motor 116756. The one you have is a 240 volt motor, not 110 volt.

1970s Motor Needed

Have Nutone Central Vac about 35 years old. Motor is making loud noise and probably needs to be replaced. Do not know model number and it does not appear to be shown anywhere on the outside of unit. Any idea where mondel no. might be without taking it all apart in order to shop for new motor? John/Jacksonville


You will be able to figure this out without the model number as there were just a few motors used back then. Take a look at the Lamb Ametek 115334 and 116765 Motors. If these do not match, take a look at all of our replacement motors or send us a photo of your motor to find a suitable replacement.

24 Volt Light Out on Unit

I have an older Eureka central vac unit, Model cv1001d. It was working fine then one day, it wouldn't start when the hose was plugged in. I notice the 24v light on the motor unit is no longer lit. I suspect, perhaps a 24 internal transformer is the culprit. What do you think or what do you suggest to troubleshoot. Thanks


Use our Troubleshooting Flowchart to troubleshoot and find the right problem and solution for this issue.

AirForce Vacuum Issue

Have a MD AirForce Power3 Control System central vac has issues. Sue West Chester, Ohio

Please call us toll free at 1(800) 997-2278 Monday-Thursday 7am-5pm PST and we will be glad to help find and resolve the issue.

AirVac AV425 Burning Smell And Sparks

I AV425 AIRVAC System. It is about 14 years old and has not been working for a while. When I use a hose or the switch on the cannister, it comes on for a vey short time and then turns off. I see sparks coming out and smell of something burning. Does it sound like a Motor issue or the brushes need to be replaced? Thank you


This indicates the motor is bad on the unit. Any burning smell is not a good sign and once this issue appears the motor is already damaged beyond repair. You can find the replacement motor on our website.

Always On

Hello, I have the SilentMaster. Recently when I removed the vacuum hose, I noticed that the power unit kept running, there was still suction at the inlets, and it didn't shut off. Now the unit won't stop unless I unplug it. If I plug it back in, it starts running again when I'm not even vacuuming. Help!


Most likely the issue is that the relay is stuck and will need to be replaced. We recommend using our Troublshooting Flowchart to isolate the exact issue with your system.

Always On

Our 15 year old nutone central didn't turn off. Then while we were away the main unit came on and was running when we got home. The vacuum hose was not connected. What can cause the unit to turn itself on. This happened several months ago?


Most often this is caused by a low voltage short. That is most often caused out-of-the-blue by the wire being chewed on in the basement or attic. Disconnect the low voltage wire from the unit and plug the unit back in. Toggle any on/off switch on the unit and see what happens. If always on with the low voltage wire from the home disconnected from the unit then the unit relay is shorted. But if it does turn off then the low volt wires are shorted somewhere in the home. Rarely does it short behind the wall inlets where they are connected but you can check that out. If you can't find the short then you will have to move to a remote control system that fits all central vacuums.

Beam 2100 Shuts Off After 10 Minutes

Beam 2100 shuts off after about 10 minutes. I just replaced the lamb 6765 motor with a new one. The unit has excellent suction. What can be the problem?


It is possible that the mini breaker failed when the motor failed resulting in the issue you described above. If your mini breaker (reset button) is on a circuit board, the entire board will need to be replaced with our Beam Circuit Board #235SB. If the mini breaker (reset button) is a separate component, you can replace it with our 15amp Mini Breaker #251.

Beam Unit Intermittent Power

Ron & Jeanne --Minong, WI--We have a Beam Central Cleaning Systems--our problem is that the system may work for a while--then quit. Other times it will quit in seconds of starting the system--then sometimes it will go off and on real quick--the system will run when switched to manual--tks.


This could be an issue with the relay or the motor. Connecting power directly to the motor will determine which problem you have. If the motor runs without issue with the power connected directly, the issue is with the relay and it needs to be replaced. If the motor will not run for at least 15 minutes uninterrupted, the issue is a bad motor that needs to be replaced.

Beam Will Not Turn Off

We have a Beam Classic Central Vac with a RugMaster Plus Powerhead. When the hose for the Powerhead is first plugged into the wall, the unit operates correctly and comes on when the switch is pushed to one of the ON positions, but it will not turn off when the switch is turned back to the off position. I initially thought it was a bad switch, but that did not solve the problem. If the hose is unplugged from the wall or if I disconnect one of the low voltage wires at the power unit, the unit turns off. Once everything is reconnected, the problem will repeat and the switch will not turn the unit off . Is this a relay problem or something else? Mike -Jacksonville,FL.


It sounds like the control board is at fault. Your actions are forcing it to reset. Replace it with our Beam Circuit Board #235SB and it should resolve the issue.

Black Soot Around Power Unit

Bob,Kings Park,N.Y. My Nutone# CV-353W unit has black soot on all the pipes closest to the unit itself. The unit runs fine.My wife is concerned! thanks.


The black soot is carbon dust from the motor brushes wearing out. Depending the dynamics, the soot may start collecting the first day the vacuum is used. On other systems, it starts collecting when the motors are about to expire. Some systems never collect soot at all because it is designed that way. We suggest you use your machine until it stops working. The soot is not harmful.

Blue Sparking - How Much Is Too Much?

I have a Galaxie GA-100 with a 3 stage motor. I'm not sure on the age as it came with the house when purchased. It has a 7.2 Ametec Lamb 116507 motor. How much sparking is too much? I see some blue sparking at the brushes as well as some yellow sparking around the armature, but I don't have any history to compare to. The motor brushes look fine upon inspection. I'm also getting quite a bit of heat and a slight smell out of the motor. Could the motor be getting tired as the suction doesn't seem too strong?

If the blue sparks are constantly wrapping around the entire center piece (armature) where the brushes ride, the motor is going bad. The smell is also an indicator that the motor is heating up and failing. The brushes may be fine but there are a lot of other "non-replaceables" that begin to go bad and lead to the motor's end. The 116507 Lamb Ametek Motor is currently replaced by the 117507 Lamb Ametek Motor. We recommend replacing the motor at this time to keep it from overheating and possibly damaging the electronics.

Central Vacuum Barely Works, Only with On/Off at Unit

Hi from Darin in Fort Saskatchewan, Alberta. We moved into our 2001 home about 10 months. It has a Kenmore Central vac system. It does not work at all now. It worked fine the last time I used it, but nothing at all now. The breaker hasnt tripped. I tried replacing the wall inlet plates, still no luck. I tried shorting the wires on the cannister and inlet plate but no luck. Tried re-setting, also. There is an on/off switch on the handle of the hose. Could this be the culprit? Or possibly the control panel or motor. If I turn power on at the cannister it does work with some suction but not the same as before. What do you think? Thanks.


This is likely caused by one of two problems. 1: The motor is basically dead and needs replacing. 2: The circuit board failed and should be replaced. If shorting the low voltage at the unit doesn't trigger the motor to start, the electronics could be bad - but if it doesn't start that could also be the motor failing. We recommend replacing the motor first, especially if the motor is fairly old. Then, if that doesn't work you can try replacing the circuit board. If you don't want to chance it, replace the entire unit.

Central Vacuum Continually Burning Out Relays


It sounds like you have a short in the low voltage wiring in the home, which could be fluttering the relay and burning it out. When you disconnect the low voltage wire to get the unit to function correctly, that tells us there is a low voltage short in the home somewhere. These are hard to find and replacing the relay may not be the final solution. We would recommend bypassing the low voltage wiring in your home with our Radio Frequency Products.

Central Vacuum Is Noisy, Smelly, and Shuts Off

Hi. We have an Electrolux, "The Boss" central vac. model # CV1801, Type D. The unit is approx. 20 years old. I vacuumed up pine needles dropped from our Christmas tree, and now despite emptying the unit (which was not full), it makes a lot of noise, smells like something burning and then shuts off. The motor will run again after it cools down, but only for a couple of minutes before a repeat of the same problem. Any suggestions would be greatly appreciated. Thanks!


The vacuum motor is dead/dying and needs to be replaced (or replace the unit with any brand such as our Silent Master, MD or FloMaster Options). If the unit cannot run continuously for a minimum of 15 minutes, it indicates a faulty motor that needs to be replaced.

Central Vacuum Left On Without Hose Attached, Is The Motor Ruined?

I have a Beam system. It is just about 1 year old. It was accidentally left running after the hose was removed for ~30mins. Now when we turn it on it makes a loud noise. Is the motor ruined?


The motor would be the one thing that would be damaged by the heat built up. You most likely have to replace it with one of our Lamb Ametek Motor Options.

Central Vacuum Trips Breakers

I have an AirVac 550A. There is a dead short in it. I plug it in and the house breaker goes immediately. I have run direct current to both motors and they appear to run just fine.


The motors may still be the issue. Please run them for at least 15 minutes continuously and see what happens. If the motors are able to run without any interruption, it could be the electronics. An electrician can replace all the electronics with the replacement board for a dual motor system handling 120V and 15amps on our website.

Central Vacuum Turns On and Off By Itself

Hi, Rusty from Frederick Md. I have a Nutone CV-350-W. Motor runs for5 mins. & cuts off, then 3 min & cuts off, until it stays on for only seconds. It's 10 years old but started acting this way 5 years ago & haven't had the $ to fix it. It does work long enough to clean my vehicle but my wife is left in the dust, literally. She wants her central vac back. After reading the other Q&A's I'm thinking I need a new motor. What do you think? What about a circut board? The model number is Lamb Electric #117465.


Yes, you need a new motor. You can save money and do it yourself. You can view our replacement options and instructions on our website.

Central Vacuum Use Immediately Pops Main Breaker

Suddenly started tripping the main breaker. Hi, I'm from San Francisco and have a 10 year old Dirt Devil 699E Platinum Force. I've never had any problems but now it will trip the breaker immediately when switched on. I also looked for a reset switch but I don't believe it has one. As it happened so suddenly I'm thinking its the relay, or could it be the motor?


That is usually the motor spiking and at 10 years old it is the most likely cause. However, the main breaker could be weak and needing to be replaced as well. Plug the vacuum into another outlet to see if it is the motor or breaker. If the breaker pops, you need to replace the motor. If the breaker does not pop, this indicates a home electrical issue.

Central Vacuum Will Not Start

I purchased a home with central vac. It does not work. When I connect the hose into the wall, any wall, even the one closest to the motor, I get nothing. Where should I start? What will it cost me to have someone come out to look at it? I know nothing about central vac systems. Jason, Massachusetts


You may be able to fix this yourself. You will be able to at least isolate the issue by using our Troublshooting Flowchart. If you would like to have someone take a look at your unit, you can use our Dealer Locator to find someone in your area.

Change Motor or Motor Brush?

Thank you for your reply. I don't know how much the unit has been used, since it came with the house I bought. I still don't know how to tell whether I should try replacing the motor brushes, or if I need to replace the entire motor. Is there a way to tell? Thanks.

We recommend replacing the motor itself in the debris canister if it has run its 800 or so hours of use. Motor brushes can be replaced around 500 hours but after that the motor itself becomes weakened at the armature and bearing.

Comes On without Hose

Why would our Fasco central vac suddenly just come on during the night? The system normally comes on when a hose is inserted into the wall fitting.

Usually the low voltage wire has been chewed through. At times it may be a bad circuit board but yours doesn't have one. Also, check the inlets to see if the contacts are being shorted by a coin or screw.

Dust Blowing Out, Not Sucking In

dust is blowing out instead of sucking in


This most often happens at the main unit because the intake from the home was connected to the exhaust of the unit. Please double check or switch them to test it. If this has nothing to do with the unit but instead the carpet brush then it is either a clog in the brush or the suction is not being activated (though it may sound like it is). Try the suction without the carpet brush attached to validate it turns on when the switch is in either position. If one position doesn't have suction then the hose switch is bad, or the main vacuum unit motor is bad, or there is a low voltage issue in the system. Use our Troubleshooting Flowchart for more help with that.

Hearing A Hum and Clicking Sound While the Motor Spins Freely

question from randy: i have a Fasco model number 851 dm that has worked flawlessly for 25 years. tghe other day while vaccumming the unit shut of on its own. standing by unit i hear a hum noise,when power is diconnected i hear a click. clicks again while plugging back in. two motor system, both motors spin freely. i am thinking power relay , but your website does not show anything like what i have. any suggestions???


The hum is the normal sound of some older unit and means nothing is wrong. It is the transformer vibrating within itself and there is no loss of electricity. The clicks you hear tell us the relay and transformer are working properly. Most likely one or both of the motors are bad (they usually do spin freely when they are bad). See if there is a reset button(s) that needs to pushed in. That may get one motor going again but not for long. We recommend replacing both motors with Lamb Ametek 116336 Motors.

Hose Causes Breaker to Pop

We have an on/off switch hose. Plugged it in and tripped the house breaker for the vacuum unit in the basement. Has worked fine for the past year. Plugged in my old hose without switch, worked fine but now it too has the issue. Any suggestions. Jaye


Your relay in the vacuum suction unit is failing and needs to be replaced. Please review the photo and details our part #242 to see if it will work with your system.