It doesn' come on when hose is plugged in. I checked that the unit was plugged in and the socket works.

Failed circuit board. Mine did the same same. Red flashing light, no power at the hose on/off switch, but would turn on manually at unit. To make sure, use a jumper wire or a quarter out of your change jar, and jump the two male power plugs on the wall socket where your hose plugs in. If it doesn't come on, then your hose is alright. I picked up a new circuit board on the net for around $80 and changed it out in 15 minutes and was a very simple fix anyone can do.

Send me a picture of the unit and I'll tell you what you need to check

Remove the hose from the unit and check the opening where it goes in. Next look inside the hose and see if you can see debris trapped in there.

When you try to clear the line you need to be in a place where its ok to get dusty. Outside, garage etc.

Shake the hose and keep at it until ALL debris is gone. Also check to see it a stick. pencil. or some other rigid item is stuck in there. If there is it will clog again.

If shaking doesn't work try a broom handle to clear the hose.

There are six different reasons a vacuum can lose suction, a plugged vacuum hose, bad motor, full vacuum bag, or cracked or damage hoses. Purchasing a vacuum cleaner can be a costly expense while repairing the suction on the unit can be virtually free. Most suction loss problems on a vacuum can be easily fixed or remedied with common house hold tools and very little technical expertise.
If your vacuum cleaner losses suction, the first and easiest solution is to check the bag. If the vacuum cleaner bag is full suction will be greatly reduced and the unit will become ineffective. A vacuum cleaner works by passing air through the bag fibers leaving dirt and debris behind inside the bag. If the refuse bag becomes full, airflow is restricted, limiting the amount of air passing through the vacuum bag resulting in loss of suction. When replacing the vacuum bag always consult your owners manual to insure that the vacuum bag seals with the vacuum inlet hose. If your vacuum cleaner bag is not tightly sealed to the vacuum inlet hose you will decrease the air flow through the bag resulting in loss of suction.
The second and sometimes most common reason for loss of suction on a vacuum cleaner is a plugged vacuum hose. If the hose becomes plugged, air flow will become restricted. To unplug a vacuum hose detach it from the machine and inspect the inside. If there is a restriction in the hose, remove it with your fingers and replace the hose onto the unit. If the hose is long and the debris is hard to get too, a broom handle or other long object can be passed through the hose to dislodge the debris. Most vacuum cleaners contain more that one suction hose, so make sure to check each one by process of elimination. Another area that can become easily plugged on a vacuum cleaner is under the lower base of the unit by the roller brush. Large debris can get caught in this area and restrict air flow to the hose.
If your vacuum refuse bag is not full and the suction hoses are not plugged the next thing to check is the condition of the hoses. Many hoses are made from plastic which can easily tear or crack. If your vacuum cleaner shows signs of wear or are cracked they need to be replaced. Even the smallest hole in a vacuum hose can leak enough air to greatly diminish the suction potential of your unit. Replace your vacuum cleaner parts with OEM parts from the original manufacturer to ensure the tightest fit.
Most vacuum cleaners contain filters. Filters are used as a last line of defense to remove dust and smaller debris particles before the air is recycled back into the environment. If vacuum cleaner filters become dirty or plugged they also can decrease the amount of air traveling through the unit. Some filters can be easily rinsed with water whereas others need to be replaced. It is important to check your owners manual before rinsing a vacuum filter.
The last and probably least common problem for a vacuum cleaner to loose suction is a bad or failing vacuum motor. Over time vacuum motors lose power due to worn carbon brushes or long term damage. A vacuum cleaners worst enemy is moisture. If water or moisture is sucked into the vacuum motor it will greatly diminish the amount of suction the unit has. Replacing a vac motor can be a costly and time consuming ordeal. In some cases, replacing a vacuum motor can outweigh the cost of buying a new vacuum. Vacuum suction is measured in water lift which can easily be measured by using a water lift gauge. If the water lift measured in inches, falls below half the original water lift specifications for the unit, it is time to replace your motor. Most vacuum cleaner repair shops carry this type of equipment and can easily tell you if it is time for a new vac motor.

Make sure cord is not damaged. Check to see nothing is blocking hose or carpet nozzle(where beater brush is or brush roll). Plug unit in to a receptacle that you know has power going to it. (Lamp you know works when plugged into same. Using hose on front, make sure bag bottom completely attached to exhaust, the hose has a little arm like thing that will depress the safety switch on the front of the unit, and turn on using foot switch at the back of the unit. If these do not work, it could be one of two safety switches, dirt may have fouled or switch may need to be replaced. Authorized Kirby Dealer in your area: Replacement parts, Kirby Distributor, call: 1-800-437-7170 United States and Canada

See if you are getting 120Vac to the main on off switch with respect to ground.

Sometimes, the plug end's have a fuse melded in to the plug in and can only be replaced.

Check to see if the bag, if applicable, is put in correctly as you will see that it pushes a trigger switch up and down, this is another biggie!

If the hose is not plugged in also some will not work for there is another sensor switch at the socket canister.

Lastly, you will have to open the unit up and trace out from the power cord to inside the vac to a module with a TRIAC on the pc board which will open on a surge. they are a 600EW is the original part and can be purchased at Main Electronic's for $3.47 CAN Ph Mike at 604-872-0267

Also, check the main switch on the vac cannister to see if voltage is passing through it first!

Best!

Robert!

Remove the hose and reinstall using the alignment arrow at the top of the hose insert. Be sure the hose clicks securely and does not twist or rotate right or left.
Then remove the power head from the wand and eliminate the wand. Plug the head directly onto the hose and plug the cord into the wire socket under the hose.
Flip the switch on the head fully back and forth to see if the head will run without the wand. If it runs put the wand back in place and inspect electrical connections and plug terminals when reinstalling. Post back with what you see and results

Define hose works or doesn't, no suction, hose will not activate vac , etc.
Test the vac by shorting across the low voltage terminals where they enter the machine. If the vac works here your problem is in the internal wiring, at the valve or the hose to wall connection. If the vac will not run, you will need to check the motor for continuity across the motor leads.

Try to plug the hose in sideways. So the top of the hose is rotated 90 degrees. If the unit turns on then there is something wrong with the hose. It might be a short or it could be a bad switch on the handle. If the unit still wont turn on I would think that maybe the low voltage wire got disconnected from the unit or there is a break in the low voltage wire somewhere along the way. Let me know if you plugging the hose in sideways works.

You will have to replace the hose asm. You can order online at:
http://vacuumsuperstore.com/F6019.html

H-90001334 (43436009) hose for $38 =s/h