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

How to Identify and Fix Common Vacuum Problems ?

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One of the easiest ways to increase vacuum cleaner suction is to empty the dust bag or container. Dust containers need to have enough space for airflow, otherwise, they could get clogged and have less suction power. Regularly check your dust compartment and empty or change it when it`s already 70-80% full.
Check for a plugged hose:

Plugged vacuum hoses are sometimes the reason for a loss in suction. Hoses can get clogged with hair, dust bunnies, string, or anything else that can`t pass through the other end of the hose. Airways inside the machine should be looked at as well. Wherever there is an air passage, check it.

If your vacuum is experiencing a loss of suction, please try the following: Check for any debris or blockages in the tubing and main body. Ensure the filter has been cleaned and left to dry as per the maintenance and care instructions. Check to see if the issue is happening on all attachments.
Vacuum cleaners are fairly simple machines. They need power to be transmitted to the vacuum to create a suction force that lifts debris. So, the usual areas that cause suction loss include the wrong height setting, stuck rollers, a faulty gasket, a broken vacuum belt, a filled bag, or a clogged hose.
Use Some Water

A little bit of water can do wonders for boosting a suction cup`s grip. Using warm water, rinse the whole cup so it softens it up. Shake the drops of water off the cup quickly and then put it up on the wall. That can often do the trick.

Therefore, the more airflow, the better the cleaning ability of the vacuum cleaner. Airflow is an excellent specification because it takes into account both the power of the vacuum motor, which creates suction, as well as the resistance of the bag and filter system that this air must pass through.
The most common cause of vacuum cleaner not picking up dirt properly is clogged air filter. Remove the filter and either clean or replace it as needed.
Many reasons can cause low refrigerant suction pressure, i.e.: low indoor temperature, dirty filters, restricted ducts, undersized ducts, closed dampers, frosted coils, restricted refrigerant line, restricted piston, incorrect piston, restricted strainer, bad indoor blower motor ect.
Low compression, an intake leak or tight valves also can cause low vacuum at idle. If the vacuum reading fluctuates within the normal range-the gauge needle bounces around a lot-uneven compression (broken rings or leaking valves or head gasket in one or two cylinders) is a likely culprit.
Suction pressure should be kept at less than 200 mmHg in adults. It should be set at 80 mmHg to 120 mmHg in neonates. [3] The catheter size used for suction should be less than 50% of the internal diameter of the endotracheal tube.
The two main indicators to determine vacuum power performance are water lift and airflow. The water lift is measured in mmH2O, mbar or kPa. It represents the suction force and is the reference parameter for vacuuming liquids and heavy materials. The airflow is measured in m3/h or in l/s.
The suction power is to be measured at the end of the tube of a complete vacuum cleaner (i.e. with tube, hose and filters – but without nozzle). Some manufacturers show the results from measurements made at the suction of the actual vacuum cleaner.
Vacuum suction pressure in adults is 120mmHg.

The lowest vacuum pressure is recommended to reduce the risk of hypoxia and tracheal mucosa injury. However, the pressure has to be strong enough to remove the secretion. Usually, it`s between 80 to 120 mmHg.

Push harder than you pull.

Many people naturally exert more force when they`re pulling their vacuums back than when they`re pushing them forward, but this can leave dirt on the floor. Vacuums are designed to be pushed forward at a rate of about 12 inches per second and pulled back at a rate of 6 inches per second.

While the Airflow measurement indicates how much air the central vacuum motor can move, the Suction measurement tells us the maximum pull the motor is capable of. This is determined by sucking a 2 inch column of water vertically to its maximum height in inches.
Use the dust brush attachment – close the blind slats so they lie flat and vacuum. Reverse the blinds so that the slats are lying the other way and repeat. Repeat monthly or as needed. Use the upholstery attachment on mattresses and fabric surfaces.
The TurboBrush® Tool has a rotating brush that easily connects to most vacuum hoses and is recommended for cleaning stairs, upholstery, rugs and other difficult to reach areas in your home while vacuuming. The TurboBrush® Tool stores on board most BISSELL vacuums for easy and convenient above floor cleaning.
The suction motor is one of the most important parts of a vacuum cleaner. It is this motor which takes the electrical power from the power source and converts it into mechanical power in the form of suction with air flow.
Start the engine and spray

Scope out all the vacuum lines under the hood. Then start the engine and spray each connection with a light stream of water. If a connection sucks in the water, you`ve found your leak. A vacuum leak can cause a rough idle, high rpm, poor gas mileage and even trigger a check-engine light.

Compressor suction pressure is too low or liquid returns, what should be done? 1) If refrigerant filled is insufficient, please add refrigerant. 2) If indoor temperature is set too low, please set it higher. 3) If filters are clogged with dirt, please replace the filters.
Overcharging leads to overfeeding the evaporator with refrigerant, which leads to higher suction pressure. Another possibility is having oversized EXV causes an overfeed to the evaporate, which increases your suction pressure.
Perfect vacuum is an ideal state of no particles at all. It cannot be achieved in a laboratory, although there may be small volumes which, for a brief moment, happen to have no particles of matter in them.
Any negative pressure significantly below standard atmospheric pressure (760 Torr/mmHg, 29.9 inHg or 14.7 PSI) is considered a vacuum.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

I have a DC07 and the brush wasn’t rotating and I had no suction at the brush but perfect suction through the hose. I noticed a large build up of dog hair around the brush so I took off the cover plate and removed all the hair, cleaned inside the floor/brush housing and cleaned out the hose. I also cleaned the filter and removed the other air access cover and made sure that they were clear. I put everything back and the brush still doesn’t turn and there is still no suction through the bottom
ANSWER : Hi and welcome to FixYa. I am Kelly.
.Here is a link that can assist you in your quest for the missing suction:
.Also Dyson has very good info on cleaning here:
. (you have to keep clicking next…)
.When you get to the part where it asks “is brush head turning?” that you say No. The site is a bit lethargic but should help you get going properly again
.Hopefully you find “Airway inspection” as part of your on-line step by step troubleshooting.
.If you still have the problem after following the steps above reply / post here and we can proceed from there.
. Kelly

No suction Hello – any help with this would be much appreciated!

I just changed the bag and filters. The machine runs, seems normal, but there is no suction. There is no blockage of the hose, as indicated by the fact that that little viewer window above where the hose connects to the unit is not showing the red portion that it shows when there is something blocking the hose (god, this is hard to describe!).

If I disconnect the hose and put my hand over the hole, I feel some suction. But

ANSWER : Well, it actually sounds like there is a blockage. Try removing your hose and dropping something through it, like a quqrter. If it comes through, no clog. If it is clogged, I believe that machine has a blower on the upper part of the cleaner (maybe in the bag compartment towards the top. You can take out the filter holder and plug the hose in there and run the unit . Does the blockage come out? If not, Try shaking the hose, or you can put a stiff wire in it to try to free it. Do not run water through it. If there is no blockage at all, then you will probably need to take it to a service center. But I am pretty confident that we are looking at a clog situation. Let me know if this fixesya! Thanks, Rene (vacuum Doctor)

My model F5906-900 — problem is the brushes have stoped working… I pulled the brush assembly out by holding the two tabs, and all seems clean and the brush assembly rotates easly… onced the brush assembly is removed. What I did notice is the female driver slot (found in the main assembly unit) that drives the brushes seems stuck..Is that normal when the machine is not hooked up to power? How can I get the brushed going??? it is a good machine, but the brush options is important too it’s ab
ANSWER : (1) Assure the Brush Control on the hood is NOT set to the OFF position.
.(2) Remove the brush assembly by pulling/unlatching it from base on each side.
.(3) Does one of the brushes have the drive pin present? It should be about ¼ inch square, and two inches long. It attaches the brushes to the drive mechanism.
.(4) Remove and clean the intake filter. One the base of the cleaner, behind the brushes, squeeze the two red abs together and pull the panel down to access the screen. Clean the hair/debris off the screen and reassemble.

Brush spin,good suction at hose, no suction at
ANSWER : Air passage from back of brush head, through the joint, and up to bag, may be blocked.

No Suction I get great suction in the hose, but when I plug the hose back into the unit, there is no suction and the air flow indicator line goes completely red. I've changed the bag and filters. I took the small panel off the back and made sure there is no clog, and took the hose off to make sure there was no clog there. Still no suction. Please help.
ANSWER : I about to say that’s always a clog of some sort that causes that

Poor Suction Heya! So I just picked up a used Dyson, but when I vacuum with it, the suction is pretty weak and it spits all kinds of stuff out the back and into my feet. When I pull the hose I have good suction, but in regular mode it hardly picks up anything. The brushes are spinning, and it eventually will clean an area if I go over it again and again. Maybe a clog somewhere? Please tell me that Dysons have better suction than my $50 Dirt Devil! Thanks!
ANSWER : I recently bought a second hand Dyson DC07. Its suction was poor. I removed all the un-clipable pipe bits and to remove any blockage but it all looked clear. The Final Sponge and hepper filter did have a lot of dust in it and the rotating brush was full of hair but nothing bad.
.I eventual gave in to curiosity and removed the three screws in the top or the yellow removable dust collection tube and cyclone bit to see what was in there. The mechanism to release the flap at the bottom of the collection tube does not allow you to remove the lid completely but it does open far enough to get inside. I found the whole top section of the yellow plastic bit blocked by a big plug of compacted dust and a champagne cork. If you are willing to take the risk and have a torx 15 screwdriver handy it that part may be blocked. It did get a bit messy.
.If I was going to attempt the same procedure I’d remove the dust collection unit from the vacuum cleaner as I did before, but leave the clear tube attached and the emptying flap firmly closed to reduce the mess from the dust falling out the bottom while cleaning the top part.

Lost suction my DCO7 lost suction in the hose I started taking it apart and cleaning it and looking for clogs (probably more than I should have) and when I put it back together it has awesome suction in the hose but no suction in the base. It just pulls the pine needles up (christmas tree) but they never appear in the “bag” compartment and when I look they are just all gathered in a clump in the bottom by the brush.
.Remove the sole plate turn the 3 plastic screws to unlock & lift off.
.Now remove the blockages that have accumilated from the oppening of short clear hose.
.Check you can turn brush roller & check belt.
.Now reassemble switch on pull handle back & look under machine is brush spinning ?
.If not check the knob on side of machine is in drive (D) position.

I have good suction at brush, but no suction in hose connection
ANSWER : I would change the bag and under the bag there is a filter, if dirty wash and make sure its completly dry before putting back into machine. once all done, have machine in upright position, turn on and see if there’s sucktion at hose. hope this helps