Zigbee Plug for Central Vac

I have a central vac system that is acting up and I don't have the time figure out where the issue is - when it's plugged into power it randomly turns on/off whenever it wants, sometimes cycling very fast.

As a short term remedy, I'm going to purchase a Zigbee plug and then just use a Samsung button to send power to it (it's in the garage). I am just concerned about having a plug that can deliver enough juice. I have no idea what kind of amp rating would be acceptable. Looking at the SonOff S31 Zigbee smart plugs as they appear to be a really good deal.

What’s the Watt rating of the motor? Any information about LRA printed on the vacuum?

I would prioritize fixing it over this proposed short-term “solution”.


First, unless the VAC has a smart control, get it fixed ASAP. It sounds like an electrical wiring problem and turning on/off remotely will not solve that safety hazard.

Circuit size. The consumption varies greatly and the 15 amp SonOff S31 Zigbee plug may not support your requirement. Look up your VAC model for a user's manual on-line and it will give you ams usage (max). If you find watts, use an on-line watt to amp calculator. I would use a Power factor of .9 to determine the amperage required of the smartPlug.


Thanks for the advice. Yes, I should explain the problem a little more. It is not a power supply or electrical wiring issue, but an auxiliary control problem in one of the wall ports. I can't find a replacement and can't seem to locate the problem. I seem to be able to keep it in 'on' from the auxiliary switch but turning it 'off' is the issue - it has power the entire time. By keeping the auxiliary switch in the 'on' position I can make the system run by simply sending power to it or not.

I can confirm that this makes sense. Basically for those not schooled in Central Vac sounds like the only way the units currently works reliably is to turn on the aux switch on the unit, vs it detecting when you plug into a port. So killing the power will shut it off without having to go flip the switch.

I actually installed these things around 10 yrs ago. If you snap a picture of your wall port (open) I might know some more. Have you contacted a BEAM dealer for parts? They were the primary supplier, but I did hear much was being discontinued so people would be left stuck unable to get parts possibly.


Thanks very much! I will follow up later today.

If JTP can't help, you could use a Zen15 by Zooz, Heavy Duty power switch and I think GE or Jasco makes one, both are z-wave

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Here is a picture. I think this one is the culprit but there's like 6 in the house. It's made my NuTone.

Those are not the ones I used, but NuTone sounds familiar, was possibly a competitor. Looks to be the same concept though. Those two pins should be spring loaded and are connected to low volt wires behind, which run back to the vac. When the circuit is closed the vac turns on. The hose has a metals ring on it which when plugged in closes the circuit.

Unplug the vac from the wall before doing this just to be safe even though it is low voltage.

You should be able to unscrew the plate and remove the whole thing if it was installed properly (not glued on). May want to disconnect the low volt wires and get in there with an old toothbrush and clean off the contacts really good. That would help if it does not want to turn on when you plug in the hose.

Now if you problem is that it is randomly turning ON by itself, that could mean a short in the low volt somewhere. Possibly right at one of the outlets if the wires are pinched behind the cover plate. Looks for any bare low volt wires and use electrical tape to insulate.

I will report back. Only in the hubitat community will a thread turn into central vac support.

I'm going to order the Sonoff plug just to try in the meantime. Amperage should work. We're having a kid in two weeks and I expect this to get pushed way down the to do list.


I've had a Beam unit for 25 years, and now in my "newish" 80's home, we have a newer Beam unit that also came with the house. I've replaced these many times before. The wires lead back to a 24v AC circuit on your vacuum. There's no chance of electrocution, so you can remove those two screws (cut away any paint at the edges so you don't pull all the paint off the wall) and pull the port out. It's not glued in, but you may have to rotate it left and right a bit to convince it to come out (and to subsequently go back in). You should see two sets of wires attached. They are usually daisy-chained to the next port, so you may see more that one set of wires on each side. It doesn't matter which terminal each bundle of wire attaches to. If you can touch the wires together and the vacuum turns on, then it's one of several possibilities.

  1. The wires were loose at the connections
  2. The springs that are supposed to push the contacts against the metal end of the hose are weak or broken.
  3. The terminals are dirty (least likely from looking at your photo).

If the vacuum turns on when the wires are touched together, but you cannot get the port to work with the hose inserted, then just replace the port. They're not expensive (around $10-15).


Will try and report back. I just called a local guy and it's like $11 to replace each outlet. The bonus is I can actually get them back to white (house is 1989 but they all turned yellow).

I also have a NuTone intercom system throughout the house but it barely works. Not yet sure what to make of it but I'd really like to get it working or replace it as monitors at all exterior doors as well as in master bedroom, basement, main floor, etc.

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So I realized that I am stupid and the problem is without a doubt at the vacuum itself. I know this because when I unplug the auxiliary control wires at the machine, it still just defaults to on no matter which way the aux switch is. I've taken it apart and cleaned it and still no luck, so I'm guessing it's an old relay or something. They don't make parts for it so it looks like I will be going with my original solution (SonOff says 15Amp and this vacuum is 11 Amp) until I can source out a new vacuum.

Thanks all.

It could also be as simple as that AUX rocker switch went bad, I have seen that before. They are typically tiny little cheap plastic toggles possibly red and black. A short can fuse the contacts together inside of it. Could be tested with a multimeter or disconnect the wires from the back of it.

I just don't know how to fix it and it's an old kenmore so no parts.

If its just the rocker switch and it can be disconnected from the back, just unhooking it should actually fix it as long as the other wires stay connected as they are. If the rocker switch is as I described above, I could find you one on amazon I'm sure.

Oh also, there is a high chance the Kenmore vac can was made by Beam / Nutone / Electrolux and just branded Kenmore. The ones I installed were rebranded Electrolux cans.

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They're pretty simple circuitry. I would tend to agree that it's likely a relay that has too much carbon build up on the contacts, the coil is burned out, or the 24v transformer has gone bad (less likely). Since you were keen to take it apart, you might consider some testing with a multimeter. That would pretty quickly identify the issue.

You will probably be able to identify the contacts on the relay failrly easily by either tracing the wires to the motor, or by labelling. C for common, NO for normally open, and NC for normally closed.

If its the transformer, you can test that by measuring the output of the secondary low voltage side. I don't want you to risk working with high voltages if you're not comfortable, so with the vacuum unplugged, measure resistance instead.


You should measure about 50 ohms on the primary high voltage side, and around 2 ohm on the 24v secondary side.

If either the transformer or relay is bad, sourcing parts isn't hard. They don't have to be NuTone parts. 110/120v to 24v transformers are an easy to source part. And 24v AC relays with contacts rated for 110/120v are also easy to source.

Thanks very much. I'll give this a whirl.