Question about Hoover U6437-900 / U6439-900 Windtunnel Bagged Upright Vacuum

1 Answer

Dirt finder I have a Hoover U6439-900.  After the cleaner was used a few times, the dirt finder light cycles between green and red on the regular setting and will not go to green.  On the sensitive setting, the red light stays on most of the time.  I have tried to run the cleaner to remove any dirt but have not solved the problem.

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert whose answer got voted for 500 times.

  • Master
  • 1,673 Answers
Re: dirt finder

The sensor may be bad, or it may be coated over with dirt. Re,ove the hose at the back of the vacuum, the head of the sensor is down inside that opening, reach in there and clean it off and see it that corrects the problem, if not replace the sensor.

Posted on Jan 06, 2008

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

1 Answer

The dirt sensor light stays green. It won't turn red, even when I know I'm picking up a lot of dirt.

The Board(46851083) is No Longer Available
The EDF Duct (47823004) EDF= Electric Dirt Finder is $20.40 from
http www searspartsdirect com model part u6485900 0517 0645000 50039309...
You can test the board by crossing the 2 connectors to "close" the circuit for the mic (small black and blue wire) while vac is running and light should go to red every time you complete the circuit. WARNING: There will be exposed electrical points on board that could cause an electrical shock!!! or damage to board if not just crossing mic connections.

Jan 22, 2016 | Hoover U6485900 Bagged Upright Vacuum

2 Answers

Hoover - Red Light Dirt Sensor

check to make sure the settings didn't get inadvertently switched to the hi position, move the switch back and forth from high to reg a few times, then leave it on reg.

remove and hand wash the primary filter and secondary filter, dry throughly and replace them in the vacuum.

if none of this works, you will need to have the vacuum serviced, or if it is still working, just don't pay attention to the dirt-finder. the dirt sensor on your vacuum is located in the suction tube and is generally not accessible enough to clean without taking the vacuum apart.

hope this helps,

Nov 20, 2007 | Vacuums

1 Answer

Hoover wind tunnel the red light dirt finder stays on

There's a microphone inside the tube the dirt runs up. It listens for dirt coming up the tube. They just go bad and there's no making it better. You can either replace that entire assembly or ignore it. Fairly easy to replace. I'll include the part so you know what you're looking at.
Good luck! The Vac Dr.

Jan 13, 2013 | Hoover Company Wind Tunnel U53019 Upright...

1 Answer

My Hoover Dirt Finder red light stays on. All

Inspection of the circuit board found that the 470uF capacitor looked damaged. I replaced it and I now have the Green and Red lights are working correctly.

Jan 19, 2010 | Hoover U6476-910 WindTunnel Upright Vacuum...

1 Answer

Hoover vacuum cleaner indicators stuck

the sensor is located in the tube that the bag mounts to, if you take the bag off of the unit and have an air compressor handy you can blow out the port hole this should dislodge the particulates that are causing the false reading, there is defintely a clog in the system. let me know if this helps thanks Don the Vacuum Doctor Alb, N.M.

Nov 05, 2009 | Vacuums

2 Answers

Red light stays on

It sounds like the plates inside the vacuum that detect the dirt have become dirty. I don't remember where they are, but I think they're accessible if you remove a certain hose. Again, I don't know which hose it is.

Jan 17, 2009 | Hoover U6437-900 / U6439-900 Windtunnel...

3 Answers

Dirt finder sensor stopped working

I had the same problem with a hoover windtunnel 6200 - u5477-900. I removed the flexible hose from top of the plastic tube running vertically along the right side of the back of the vacuum. When I used a flashlight to look into the plastic tube, I could see a clog at the bottom, where the flexible hose curved frontwards towards the brushes. I then removed the 2 screws holding the vertical plastic tube to the vacuum. When I disconnected the plastic tube from the flexible hose at the bottom, I found a clog of dirt and dog hair. After removing the clog and reassembling, the clean / dirty light now moves back and forth from red to green.

Jan 29, 2008 | Hoover U6437-900 / U6439-900 Windtunnel...

4 Answers

Embedded dirt finder light stuck

The Hoover uses a small microphone that is positioned in the plastic housing that the end of the hose fits into, just behind the bag compartment. What happens is that when dirt comes up the hose and hits the 90 degree corner, just before it enters the bag, the microphone picks up the sound and transmits that info to the electonics that controls the lights. Sometimes the microphone will stick and the red light will stay lit. If you take a screwdriver and give the microphone area a sharp tap with the handle of the screwdriver, this will often jar the microphone and it will begin working again. If not, it may need to be replaced. NOTE: this function does not affect the cleaning efficiency of the vacuum. Your vacuum will still work normally whether the dirt sensor is working or not. It is a totally unrelated function to the vacuum itself.

Dec 31, 2007 | Vacuums

1 Answer

Embeded Dirt Finder

check out the switch that activates it. go to thehooverstore for a complete listing of hoover machines. I'm sure you'll find your machine listed along with an exploded diagram of the machine

Sep 19, 2007 | Hoover U6437-900 / U6439-900 Windtunnel...

1 Answer

Hoover Savvy

Does this happen at both Dirt Finder Sensitivity settings?

Sep 16, 2007 | Hoover U8171-900 / U8172-900 / U8173-900 /...

Not finding what you are looking for?
Hoover U6437-900 / U6439-900 Windtunnel Bagged Upright Vacuum Logo

849 people viewed this question

Ask a Question

Usually answered in minutes!

Top Hoover Vacuums Experts


Level 3 Expert

18258 Answers

Roger Potts

Level 3 Expert

694 Answers

Ryan S
Ryan S

Level 2 Expert

328 Answers

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

Answer questions

Manuals & User Guides