I have a Johnny Vac and my carpet head isn't on and spinning.

on the head there is a round filter type part if that is pushed in the the brushes won't turn. try pulling it out slightly.

Do you mean the beater bar stops turning and then it doesn't vacuum?
Or it shuts off when you jam it full of carpet? Read the below manual:
http://www.sebo.us/pdfs/website_owners_manualsPDFs/AIRBELT%20K%20Manual.pdf

Hi Denise,

DC14 is engineered to adjust automatically to suit the type of flooring you're using it on. You can also use the brush control on the cleaner head to turn the brushbar on for vacuuming carpets, and off for vacuuming hard floors.

However, if you're concerned the cleaner doesn't seem to be working correctly, please follow the steps shown in our online support guide to identify and resolve any issues:

http://www.dyson.com/support/help.asp?article=626&product=DC14-ANIMAL_US

If you've tried this and still feel the cleaner isn't picking up as well as usual, please get in touch with us directly so we can help - you can call us free on 0800 298 0298 (UK), or 1866MYDYSON (US).

Kind regards,

Jack
Dyson Online Customer Support

Here is the manual for that model.

Hi there,

Sorry to hear you're having difficulties with your DC14. If the brushbar won't run when the cleaner is in contact with the carpet, it's probably best if you get in touch with us directly. One of our experts will be happy to run through some troubleshooting over the phone with you, and recommend the best course of action. You can call us free on 08002980298 (UK), or 1866MYDYSON (US). We'll look forward to hearing from you.

Kind regards,

Jack
Dyson Customer Service

Check to see if the brush is turning when you have the vac on and the handel down 'of course keep your hands from that area when doing this ,you might have to lean the vac ,to see the resaults.

Hi dear.There are two type of attachments for this vacuum cleaners to pick up the pets hair,fluff & so on.They call it"Turbo & Power Brush".Turbo brush operates with machines suction & Power one operates with small electric motor which is built in the unit.They work with the same prenciple.There is a belt drives the rotary brush.OK.there are two small yellow screw underneath the unit.Please undo them,take of the cover & clean the rotary brush,check for the belts tension.It should be enough tight to drive the brush.If not ask for spare part from Miele in your country.After cleaning please put it back in order.To test it,attached to the vacuum.Turn the power on for Turbo brush,as long as suction starts,brush should start turning too.For the Power one,there should be power button on the handle to turn it on & off.Press it.It should work.On both of the unit,brush should spin good & strong enough to do the job when it's attached the surface you are vacuuming.Check the brush after each use,cleaned if neccesary. I hope that helps.Thanks.

Lift the headlight and rotate the thumb dial to release the carpet head. It will spin to the side. Rotate the square handle at the front of the vac fully to the left.
Remove the carpet head and open it from the bottom side. Observe which side had a little block below the LED belt indicator when you rotate the brush. The brush must go back in this way. The blocks at the end of the brush are color coded for height adjustment. Remove the brush, slide a genuine belt onto the center and close the bottom cover of the housing. make sure the brush spins freely, now look into the belt opening, round hole at the side. Using the square dial at the front of the head, rotate the hook into the belt to twist the belt and open it for installation onto the motor shaft.
Reinstall the head onto the vac, using the thumb dial to lock into place and rotate the square handle again . This will release the belt tension onto the motor shaft. Raise the vac up two knotches with the pedal before lower onto the carpet.

Depending on the model you may have a single or two motor system. If it is not running well in carpet mode but still has suction check to see if the brush for the carpet head is turning. If not look for a red reset switch or spin the brush when the vac is shut off. It it spins freely the belt is either broken or badly stretched and needs replacement.

when you install the hose connector it trips a switch that switches the vac motor into high speed because the vac path is longer using the hose. check the belt after you remove the front. make sure the direction of rotation is in the direction of belt travel stamped in the impeller. try adjusting the head height