Central vac won't shut off

My wife was vacuuming over the weekend and when she withdrew the hose from the wall, the central vac continued to operate. The only way we could get it to shut off was to physically unplug it at the main unit (where the bag is). I checked the contacts at the wall plate - they seem ok - and I emptied/replaced the bag. Any other ideas as to what the issue might be?
Thanks in advance for any thoughts you could share...
-Dave
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Dave DesRoches wrote:

If checked all the outlet, stuck relay on the control board may be the culprit. Tony
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Dave DesRoches wrote:

Stuck relay is a good possibility that will be on the vac where the low voltage wires attach. However it is also possible you have a short somewhere in the low voltage wire system. Disconnect one of the low voltage wires from the central unit. and plug it back in. If it still runs the wiring is OK. if it does not run until you reconnect that low voltage wire then the problem is the wiring. My guess would be at the outlet that was being used when the problem was discovered.
--
Joseph Meehan

Dia duit
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Wow, that's gotta suck.
sorry, I couldn't resist.
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I see lots of good advice here already. Might I suggest that, from the way it occurred, the little "lever" or arm, inside the floor/wall fitting may simply be "stuck" in the pushed in position? That was the problem with ours, anyway. When you insert the hose, the metal pipe is one side of the ckt, the little arm the return part. I just happened to notice one looked "different" than the others when I was studying them to see exactly what turned the vac on.
There is a logical way to troubleshoot the system; it's pretty easy to do. If still no joy but you have access to a meter that can measure the voltage used in the wires, come on back. It could be done without a meter, but the meter just makes it easier; less running around. The voltage in the wires that turn it on are harmless, but beware the 110V ac: THAT is very dangerous! Also, if you feel ambitious, it's handy to have a central vac on a GFCI since it runs unattended all the time. Assuming yours isn't hard wired, there are plug-in GFCI's available. They're about $9 around here.
Regards.
Pop
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Disconnect the low-voltage line from the vac unit Does the unit still continue to run - if so you have an issue with the vac unit (stuck solenoid) Check the disconnected low-voltage line for a short - use a multi-meter if short discovered then it's a process of elimination on where it is located - 1st check the dust-pan outlets (if you have any - sometimes they don't close correctly and leave a short in the low voltage line) Work around each of the other outlets - disconnecting the low voltage line from each of them (a pain I know) and again check for shorts, with the multi-meter If they are all disconnected (outlets), and the short is still there - it's on the line somewhere - look for damage if you can (rodent maybe),
I had the opposite - I had an installer rough in the vac pipes and cables, but he put a kink in the low-voltage line that gave an open circuit - just as it entered the garage (so I discovered).
-Mike
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