Tip & How-To about Hoover Ultra U6430-900 WindTunnel Bagged Upright Vacuum

How To Replace The Thermal Overload Switch on Hoover Windtunnel Uprights

All Hoover Windtunnels have a safety feature that will shut down the motor if it starts getting to hot, which prevents the motor from burning out. Usually after this switch trips itself you just need to let the machine cool down for 30-45 minutes and it should come back on. Sometimes even after clearing a clog, or replacing the filters and bags, the vacuum will continue to cut off. If you're absolutely sure that there's no obstructions, or other things that are causing the motor to overheat, then the thermal reset switch itself may have gone bad. Usually you can tell when the switch is bad by feeling the motor cover immediately after the machine shuts off. If it's warm or hot to the touch, this indicates there is something still stuck in the machine. If it's not hot, this means usually the thermal switch itself has gone bad.

Here's how you can replace this switch. Again, it's very important to check all other possible fixes before attempting this repair.

What you'll need to do this repair:

  1. Phillips Head Screwdriver
  2. T20 Torx Bit Screwdriver
  3. Hoover Windtunnel Thermal Reset Switch (this varies from model to model, please contact us to find out which exact one your model uses)

Use a countertop or work bench, and turn the vacuum cleaner upside down so that the handle is resting on the floor, and the brushes are facing upwards. Unscrew the four screws on the corner of the bottom plate that covers the brush roller:

Remove the bottom plate, then pull the roller brush and belts out of your machine. There are 3 screws that hold the top brush cover in place that need to be removed. On the right side the screw is down below the transmission to the right. There's also a screw in the agitator tray, in the middle that needs to be removed. NOTE: This small screw in the agitator tray is only present on some models, may or may not have this little screw, but all models will have all other screws circled. I have circled both screws that need to be removed:

The screws on the left side that need to be removed are also circled. One screw holds the upper brush cover on, and the other two screws secure the hose in place. Remove all three screws as well as the transparent hose cover:

After all of these screws have been removed, there are two clips that are the last things holding the top brush cover onto the vacuum. Use a flat head screwdriver to push these clips off on both the left and right sides. The right side clip is near the pulley that the flat belt rides on, and the left side clip is next to the internal hose.

After popping these two clips out, put the machine on top of the table or work bench, and remove the top agitator housing. You'll see on both sides of the vacuum, two metal brackets that have two black screws. These brackets actually secure the agitator housing to the upright part. All four screws need to be removed from the machine.

After removing the 2 brackets from the machine, you'll now to need to release the self-propelled cable from the agitator housing. Unscrew the 2 screws that are circled (in red), then use your Torx T20 Screwdriver and remove the washer and screw from the actuator arm on the transmission (circled in green)

You will now be able to completely remove the agitator housing (the plastic housing that roller brush fits into) from the rest of the vacuum cleaner. It's best at this time to remove the door that covers the vacuum cleaner, as well as removing the bag itself. Next, remove the two silver screws that hold the headlight lens in place, and remove the lens:

After the headlight cover has been removed, you'll now have access to the light bulb. Unscrew the black screw that secures the headlight. Now you'll need to remove the motor cover to get inside the motor compartment. There are 5 long screws that hold this cover down, two of these are underneath of the plastic piece directly above the headlight (on some models, the dirt finder controls that turn red and green when the floor is clean):

If your model has an "Embedded Dirt Finder" control, carefully turn the plastic housing over so that the circuit board inside is facing you. You can see at the top of the circuit board housing two plastic clips. Simply pull these two clips back with your hands, and release the circuit board from the plastic housing.

There are two wire harnesses that connect onto
this circuit board that need to be removed also. The larger terminal that has the black and white wires has a simply clip that you press, and pull out, the smaller blue and white wire terminal just simply pulls off without having to press a clip.

After removing the circuit board, you'll see a foam part where the headlight, and the two wire harness from the circuit board go into the motor housing. Simply use a pair of needle nose plyers and pull upwards on this foam part to remove it:

Now you can remove the motor cover, and get direct access to your motor. The thermal reset switch is located on the orange wire, right before it connects into the motor terminal. I have highlighted the actual thermal switch in the picture below.

I found that it's much easier to splice the new orange wire to the old wire as opposed to opening up the entire rear of the vacuum to get access to the other end of the orange wire. Cut the existing wire where I have marked it with an X in the picture of above, and use a simple Wire Nut to attach the new orange wire to the old one.

After splicing the two orange wires together, simply re-install the motor cover over top of the motor. Now plug the machine in and let it run for 15-20 minutes while the machine is still apart, just to ensure that the new thermal switch corrected your problem. If the machine did not cut off while testing it, great! Simply put the machine back together and you'll be back to vacuuming.

I really hope that this repair tip was helpful. Due to the complexity of this repair, and the length of time it takes, most vacuum repair shops will charge a lot of money to do this. Hopefully with this guide, you'll be able to complete this repair on your own.

If there's a step that you don't fully understand, or if you have any follow up questions, please don't hesitate to use the comment field, or the clarification request, and I'll be happy to answer any questions for you.

If you need to obtain any of these parts for your vacuum cleaner, please visit our website. Here's a link to most of the Hoover Windtunnel parts that we sell online. If you need something that's not listed, feel free to give us a call or use our online live help chat.
Hoover Windtunnel Parts & Accessories

If you found this repair tip helpful, please be so kind and rate my repair helpful, or leave me some feedback.

Thank you,

Chris Jones

Posted by on

Hoover Ultra U6430-900 WindTunnel Bagged Upright Vacuum Logo

Related Topics:

Related Questions:

1 Answer

while vacuuming with my hoover mach 5 it all the sudden shut down

Hi, If it is warm to the touch, and it just shut down all of a sudden, I would say that the motor has an internal over load switch that is normally closed, and opened to stop from burning this vac out. It is a built-in safety. I would look at the roller for anything that may have hung up, but steady use for an hour just over heated the motor. Let it cool way down. Try and start it. Also, check the plug to see if you may have lost power there also. Let me know please so I can be of any help you may need.

Nov 08, 2009 | Vacuums

1 Answer

The region of the motor gets very hot during use. What can I do?

The Hoover is likely built with a temperature overload protector, to shut down the unit if it gets excessively hot. All the units will get heat build-up from the suction motor during use.

Sep 29, 2009 | Hoover Vacuums

1 Answer

Hoover Cyclonic Fusion Vacuum overheats and shuts off.

If it gets too hot it will shut down for about an hour...it does that to protect the motor. A lot of tools and work appliances seem to have that feature nowadays.

Jan 09, 2009 | Hoover Fusion Plus Cyclonic Upright Vacuum...

1 Answer

Motor gets hot in moments and shuts off

True, the motor has safety measures to stop it from overheating... that's why it shut down. You smelled something, so some kind of damage was done. It's possible that the over temp switch itself got fried. Doesn't sound too good from here.

Mar 08, 2008 | Filter Queen Majestic Canister Vacuum

Not finding what you are looking for?

3,719 people viewed this tip

Ask a Question

Usually answered in minutes!

Top Hoover Vacuums Experts

Les Dickinson
Les Dickinson

Level 3 Expert

18411 Answers

Gerry Harvey
Gerry Harvey

Level 3 Expert

1474 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers

Are you a Hoover Vacuum Expert? Answer questions, earn points and help others

Answer questions