Old Nutone central vac system turned itself on and ran for hours
It is a model 350. Probably original to my house, about 25years! Is this some simple fix or do I need to replace the main unit? It has worked perfectly otherwise.
Vacuums - Broan-NuTone - VX475 Bagged Central System Vacuum
Answers & Comments
If your unit normally turns on when you open the flap on the wall inlets then you should check each inlet for a switch or a button, sometimes those buttons can get loose and fall into the wall making the unit stay on. if your unit normally turns on when you plug the hose into the inlet then it would probably be a relay usually on the main tank itself try locating them and gently tapping on them with the rubber end of a screwdriver to see if you can un-stick them.