Your Sirena has lost suction

The hose grips but doesn't pull. The nozzle no longer lifts the carpet pile. Or you notice it by the sound: the machine runs, but the air coming out of the back is weak. It is almost never the motor. In the great majority of cases something is choking the airway, and every one of those points can be checked in ten minutes, with no tools.

First of all: listen to the motor

If along with the loss of power you hear a new humming, or the speed rising and falling on its own, stop the machine and do not switch it back on. That is not a suction problem: those are the carbon brushes at the end of their life. One more use is enough for the metal holder to score the armature, and there is no coming back from that.

If the motor runs steady and clean, work through the list in order. It runs from the most likely and cheapest to the rarest.

1. The HEPA filter

By far the most frequent cause. The filter catches what the water did not stop, and little by little it clogs: the machine keeps running, but it is breathing through a wall. Pull it out and hold it up to the light. If no light comes through, that's your answer.

Rinse it with water only, at least every four months, and let it dry completely before refitting it — a filter put back damp clogs again within weeks. After twelve to eighteen months there is nothing left to save: the fibres stay closed even when clean.

with the illustrated three-step instructions

2. The separator

This is the part that spins the water and separates dirt from air. Over the years it scales up with limescale and dry dirt, and less air gets through. Take it out and look at the vanes: if they are covered in a hard film, clean them with the brush made for the job. If limescale has eaten or chipped them, the separator has to be replaced.

3. The hose insert

The insert is the rigid end that goes into the machine. In time the plastic cracks exactly where the hose bends most: the crack is fine and often invisible, but through it the hose draws air from the room instead of from the floor. Try covering the hose mouth with your hand while the machine is running: if you feel air getting in somewhere else, you have found it. You can change it yourself, with the proper glue.

with the replacement video

4. The hose

Last, because it is the most expensive and because it is rare. If the insert is sound but the power does not come back, the hose may be split inside, under the sheath. Bend it slowly along its whole length with the machine running: where the flow changes, there is the split.

If you have checked all four

Then it is worth looking at the machine rather than at the parts. Message us on WhatsApp: send a photo of the filter and of the separator and we will tell you whether an overhaul is due.