A Dyson V12 Detect Slim that has lost suction has a blocked or clogged airway in most cases, and the machine's light weight and slim design make the checks quick. This is a lightweight cordless stick with a click-in battery, a green laser that shows dust on hard floors, a particle counter on the LCD and a washable filter. The laser and the particle counter are detection features, not parts of the suction system, so a dull laser or a stuck count does not explain weak pull.
The checks in more detail
What does is the airway: the head, the wand, the bin inlet, the cyclone and the filter. Start with the cleaner head. Switch off and detach it, look at the brush bar and cut away any hair wrapped round it; a bar that cannot turn also stops the head picking up. Look through the head's air passage for a blockage. Then the wand: hold it up to the light, and if it is dark, push a long, soft object through it.
Clear the bin inlet, which narrows where hair gathers, and remove the bin to inspect the cyclone for hair and fluff. Empty the bin, which should not be filled above the maximum line. Then the filter. Pull the washable filter free, tap out the dust and rinse it in cold water, squeezing gently, without soap. Stand it somewhere warm and airy for at least 24 hours until it is completely dry; a damp filter cuts airflow and smells.
Refit it with its seal in place. Check that the battery is charged and clicked in, since a weak battery reduces the motor's power, and that you are not in the lowest power mode. Test suction with the head off by holding your hand at the wand's end. If suction is weak with a clear airway, a dry filter and a charged battery, contact Dyson with the serial number from the label on the machine's underside.
Differential
Likely causes of “Dyson V12 Detect Slim vacuum has weak or no suction”, and how to tell them apart
- 1
Hair on the brush bar or a blocked head
What separates it The head does not pick up
How to confirm Cut the hair and clear the head
- 2
A blocked wand or bin inlet
What separates it Suction is weak at the end of the wand
How to confirm Clear the wand and inlet
- 3
A full bin or a clogged cyclone
What separates it Dust escapes and the pull is weak
How to confirm Empty the bin and clear the cyclone
- 4
A damp or clogged filter
What separates it Suction fades
How to confirm Wash and dry for 24 hours
- 5
A weak battery or low mode
What separates it Pull is weak on a low charge
How to confirm Charge the battery and raise the mode
Before you touch a setting
Record this first — changing settings destroys the evidence
- Where the suction is weak
- When the filter was last washed
- The battery charge and mode
- The serial number
Try in this order
0 of 6 completedDetach the head
ReversibleCut hair from the bar.
Check the wand
ReversibleLook through it.
Empty the bin
ReversibleAnd clear the cyclone.
Wash the filter
ReversibleDry for 24 hours.
Charge the battery
ReversibleChoose a higher mode.
Contact Dyson
ReversibleIf still weak.
Model-specific
What is true of this model and not of its siblings
- The airway
- Head, wand, inlet, cyclone and filter form the path.
- The laser
- It reveals dust on hard floors and is separate from suction.
- The filter
- Wash it monthly and let it dry fully.
- The battery
- A weak charge lowers the pull.
- Modes
- A low mode is deliberately gentler.
- Dyson help
- Quote the serial number from the label.
Stop boundary
When this stops being a self-service repair
- !Switch off before taking anything apart
- !Do not use a damp filter
- !Contact Dyson if the pull is weak with a clear airway
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why has my V12 lost suction?+
A blocked airway or a clogged filter.
Does the laser affect suction?+
No, it is a detection feature.
How long should the filter dry?+
24 hours.
Can the battery cause it?+
A weak battery reduces power.
Is the particle counter related?+
No.
Where is the serial number?+
On the underside.