It won't start at all not clogged waited overnight still wont start

could be the motor thermostat. Make sure the unit is clean. No dust build up in the filters etc. Then here are the motor reset steps.

Motor Thermostat needs resetting

In order to reset the Motor Thermostat:

1. Move the Power Button to the "O-Off" position
2. Unplug the vacuum
3. Check for a clogged hose or filter; unclog the hose and replace the filter
4. Wait 45 minutes for the vacuum to cool; then plug the vacuum
5. Turn the power switch to the "I-On" position to start the vacuum
6. If the vacuum still does not start, contact Customer Service at 1-800-798-7398

I am having the same problem.. any answers??

dave, the thing that causes many problems is dirt, air blow everything in the mechanics , this may help a lot

Add CLR to water tank. Let it sit for an hr to overnight unplugged. Plug back in, turn on steam to medium setting and wait about 20 minutes. Mine started to steam and I let it steam for 5 min or so. Empty out CLR, add only "DISTILLED WATER" and clean away. Good luck.

Possible bad cord, or bad plug at the end of the cord. Take it to a vacuum repair shop

Same thing happened to me. I checked the owner's manual and it turns out the Eureka Envirovac has a built-in thermal cut-off switch. So anytime the motor gets too hot, it just shuts down. Most of the time this is because it gets plugged or the filter is too dirty. In my case, the dust basket thingy and filter were clogged beyond belief. Probably would help to clean that more regularly in hindsight. Supposedly it will turn back on after the recommended 30 minute wait.

I'm not sure it has one. Check the owner's manual though.
Try this. Turn off vacuum. Unplug it. Make sure there are no clogs in main hose, power head intake tube, or intake inside tank. Plug it in, turn it on, and let us know what happens.

Vacuums have a heat activated breaker in them. Is the action end hot? If you get a clog, the motor won't get the air blowing through it and it will overheat causing the breaker to blow. If this is the case, wait (sometimes a few hours) for it to cool while you check for clogs then try it again. Hope this helps!

brushes probably worn out
take it in for a service or junk it and get a new one