Vacuum pulsing on and off, or cutting out
On Dyson V7 to V15 sticks, the motor pulses when it detects a blockage, and it won't run normally until you clear it. The V6 cuts out instead, to cool down.
What the pulsing means
Dyson's manuals describe it the same way for the V7, V8, V10, V11 and V15: the motor switches on and off in quick succession when something is blocked, and after a number of pulses it may cut out. The V10 big-bin manual says six pulses; the V15 and V11 screens also show a blockage alert. Dyson's V7 and V8 support pages list three causes:
- A blockage in the wand, head, bin inlet or main body
- A stuck bin inlet
- Filters that need washing
The V6 behaves differently. It has a thermal cut-out that switches the motor off when it overheats, and Dyson says to let it cool for 1 to 2 hours before checking.
Fix it in this order
Safety: Take the vacuum off the charger and keep your finger off the trigger while you check for blockages.
- Let the machine cool for a few minutes (1 to 2 hours on a V6).
- Empty the bin and remove it. Look into the main body inlet and the bin inlet, and clear anything stuck there.
- Take the wand off and check both ends. Clear anything inside by hand or with something blunt, never anything sharp.
- Check the neck and underside of the floor head, and take the brush bar out if hair is jammed around it.
- Wash the filter or filters in water only, no detergent, and let them dry for at least 24 hours. Use a spare filter in the meantime if you have one.
- Refit everything and test. On the V11 and V15, the blockage alert should clear.
Dyson's warranty doesn't cover clearing blockages, so damage done with a sharp tool won't be covered either.
Shark cordless and uprights
Shark doesn't use pulsing as a signal. On a Vertex, a red nozzle light means a blockage, and a blinking red nozzle light means it overheated: clear the blockage and wait 60 minutes. On a Navigator upright, a flashing red brushroll light or a sudden shut-off means the thermostat has tripped: unplug, empty the cup, clean the filters, clear blockages and wait 60 minutes.
If it still pulses
If the filters are clean and dry and nothing is blocked, contact the manufacturer. A pulse that continues with a clear airway can point to a battery or electrical fault, and those parts aren't owner repairs.