Safety first. Everything below is an external check any owner can safely do. Do not open a battery pack, work on exposed wiring, or bypass a safety cut-out. If a product is hot, smoking, swollen or physically damaged, stop using it and call us.
Suction is airflow. When it drops, something is restricting that airflow — and the restriction is usually somewhere you can reach.
Filters
The most common cause by a wide margin. Filters need washing periodically and, critically, need to dry completely before going back in. A damp filter chokes airflow and can trigger a cut-out. Drying properly takes considerably longer than people expect — leave it far longer than seems necessary.
The bin and its seals
Empty it, then look at the seal around the bin opening. A seal that is dirty, distorted or not seating properly lets the machine pull air from the wrong place, which costs you suction at the floor.
The wand and hose
Detach the wand and check straight through it. Blockages love the bends. With the wand off, test suction at the body directly — if it is strong there and weak with the wand fitted, you have localised the problem.
The cleaner head
Hair and fibre wrap around the brush bar and build up in the head's inlet. Check the brush bar turns freely and clear anything wound around it. On hard floor heads, check the inlet slot itself.
Intermittent rather than constant
Suction that comes and goes, or a machine that pulses, more often points at a partial blockage or a filter than at a motor. Constant weak suction across every configuration is the case that more often needs a technician.
Still stuck?
Call a product specialist and describe what yours is doing.