Automatic height adjustment not working - Sebo X4 Bagged Upright Vacuum

If the height adjustment on your Bissell PowerForce Helix Turbo Rewind vacuum is not functioning properly, there are a few things you can try to fix it:

1. Make sure that the height adjustment lever is being pressed down all the way. Sometimes the lever can get stuck in the "up" position, which prevents the height adjustment from working.
2. Check the height adjustment mechanism to make sure it is not damaged or obstructed. This may involve removing the vacuum's dustbin or base plate to access the mechanism.
3. If the height adjustment lever and mechanism are functioning properly, the problem could be with the vacuum's belt. The belt is responsible for driving the height adjustment mechanism, and if it is stretched or damaged, it may not be able to move the mechanism properly. In this case, you may need to replace the belt.
4. If none of these solutions fix the problem, the vacuum's internal hardware may be faulty and will need to be repaired or replaced. You may need to seek the assistance of a professional for this type of repair.

This vacuum cleaner has no height adjustment. You can run it across any type of carpet without making adjustment. You should turn off brush roller when using on hard floors.

Take it to your local Sebo dealer for repair. Sounds like the servo has gone bad.

Hello! The M085435 has an automatic height adjustment. The vacuum will adjust to the carpet height without you having to do anything. Hope this helps!

It has automatic height adjustment.

It's likely the circuit board that controls the height adjustment motor, or the motor itself. Your local sebo service center will be better able to test to see just what is wrong. Though it wouldn't hurt to take a look at the boards sometimes they're visibly burnt, or connections can be loose. Good Luck!

This model claims to have automatic adjustment. It has two foot pedals at the bottom which gauges the height of the carpet/floor. There's no other way to adjust the height.

Assuming that the automatic height adjuster is working properly, most likely your Sebo needs a new brush roll because the bristles on the old one are worn to the limit. To test the height adjuster, put the machine in the normal operating position (with the handle not upright) then switch on - the green "down" light may come on briefly (or may stay on if the brush is worn). Then, leaving the machine switched on, move the handle to the locked upright position - the green "up" light should come on, and you may be able to see the whole machine tilt backwards slightly as it lifts the brush off the floor. If that happens, the adjuster is working properly and you definitely need a new brush roll.
I hope this helps. If you need more guidance, just post a reply here and I'll get back to you soon. Please remember to rate this answer as I do value feedback. Good luck!

Worst case scenario is that there's a fault on the circuit board, but another possibility is that the brush roll is not rotating freely. The automatic height adjustment works by sensing the drag on the brush roll, and altering the height to maintain constant drag. So, if the brush roll is sticking, the sensor detects the extra drag and raises the height accordingly. First thing to do, then, is remove the brush roll and remove any hair (the most common problem) or other stuff that may be wound round it - especially at the ends near the bearings. Check that the brush roll is able to rotate freely.
If this doesn't solve the problem, the next possibility is that a spring has broken in the clutch/sensor device where the two drive belts meet. That will cause the sensor to "think" there's more drag on the brush than there actually is, and hence to raise the height as before. This clutch (which isn't really a clutch) has two toothed pulley wheels - one driven by the belt from the motor, the other driving the brush roll. Holding one wheel stationary, the other can be rotated slightly and there should be increasing resistance to that rotation. If the spring has broken there will be no resistance until you reach the limit stop. Unfortunately, if you've no experience of these units, it can be really difficult to know whether one is broken or not! The third possibility - failed circuit board - is, in my experience, the least likely. These are typically extremely reliable, and will usually last the life of the machine (25 years or more). I've never known one fail, but it's always possible.
I hope this helps. Any questions, just post here again and I'll do what I can. Please remember to rate this response. Thanks!