A Dyson Big Ball that has lost its suction at the floor head has a blocked or leaking airway somewhere between the machine and the floor, and the way to find it is to test the route in sections. The Big Ball is a corded cylinder vacuum: a wheeled body with a hose, a wand and a floor head. Because the cleaning tool is at the end of a long path, a fault anywhere along it shows up as weak suction at the head, even though the motor is running at full strength.
The checks in more detail
The self-righting ball body and the washable filters add little to the diagnosis, which starts at the end of the airway and works back. Begin with the floor head and the wand. Disconnect them and look through the openings for hair, string, a sock or a crumpled paper; hair wraps round the brush bar and blocks the inlet of the head. Cut away hair, check the brush bar spins and look into the wand with a flashlight. Then test the hose.
Pull the hose from the body and block its end with your palm: if suction at the body is strong, the machine is fine and the blockage lies in the hose, the wand or the head. Flex the hose along its length, looking for a kink or a bulge, and shake it to hear a rattle of a trapped object. Check the connection points for cracks that let air in, which also weaken suction. Then the body. Empty the bin, which should never be filled past its maximum line, and pull off the cyclone shroud to clear hair around it.
Wash the filter or filters in cold water, following the manual, and dry them for a full 24 hours before refitting: a damp filter cuts suction and can cause the motor to cut out. Check the seals for splits. If suction at the body is weak even with the hose off, a clean filter and an empty bin, the motor may have failed or the airway inside the body is blocked; contact Dyson with the serial number from the underside of the body.
Differential
Likely causes of “Dyson Cinetic Big Ball vacuum has weak or no suction”, and how to tell them apart
- 1
A blocked hose, wand or floor head
What separates it Weak suction at the head and strong at the body
How to confirm Test and clear each section
- 2
Hair wrapped on the brush bar
What separates it The head will not pick up
How to confirm Cut the hair away
- 3
A damp or clogged filter
What separates it Suction fades over time
How to confirm Wash and dry for 24 hours
- 4
A full bin or a clogged cyclone
What separates it Dust blows back into the bin
How to confirm Empty the bin and clear the cyclone
- 5
A cracked hose or seal
What separates it A whistle or a hiss
How to confirm Replace the part
Before you touch a setting
Record this first — changing settings destroys the evidence
- Where suction is weak: head, wand, hose or body
- Whether the filter was washed and dried
- Whether hair is on the brush bar
- The serial number
Try in this order
0 of 6 completedDisconnect the head and wand
ReversibleLook through them.
Block the hose end
ReversibleTest suction at the body.
Check the hose
ReversibleFor kinks and bulges.
Empty the bin
ReversibleAnd clear the cyclone.
Wash the filter
ReversibleDry for 24 hours.
Contact Dyson
ReversibleIf the body is weak too.
Model-specific
What is true of this model and not of its siblings
- The airway
- Body, hose, wand and head form one path; a blockage anywhere weakens the head.
- The test
- Blocking the hose end isolates the body.
- The filter
- It must be washed and fully dry.
- The bin
- Keep it below the maximum line.
- Seals
- Splits let air leak.
- Dyson help
- Quote the serial number from the underside.
Stop boundary
When this stops being a self-service repair
- !Unplug before taking anything apart
- !Do not use the vacuum with a wet filter
- !Call Dyson if the body is weak with a clear airway
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why does my Dyson cylinder have no suction?+
A blockage in the airway or a clogged filter.
How do I test it?+
Block the hose end at the body and feel the pull.
How long should the filter dry?+
About 24 hours.
Can a crack cause it?+
Yes, air leaks reduce suction.
Is the motor the problem?+
Only if the body is weak with a clean airway.
Where is the serial number?+
On the underside of the body.