Where is the cabin filter on an Opel Movano B?

On the Movano B (2010-2021), the cabin filter is located behind the glovebox on the passenger side. To reach it, open the glovebox, squeeze its side walls so that they clear the catches and lower it. The filter is directly opposite, beneath a plastic cover. Remove the cover, slide out the old element, insert the new one at a slight angle and refit the cover. The whole operation takes a few minutes and requires no tools. Note the airflow-direction arrow moulded into the filter frame and housing. A filter installed backwards performs less effectively and blocks more quickly.

How often should it be replaced, and what are the signs of blockage?

Replace the cabin filter once a year or every 15,000-20,000 km, and more often when driving on construction sites, unpaved roads or in urban traffic. Typical signs of blockage are weak airflow despite the blower being set to maximum, windows that take a long time to demist and a musty smell when the ventilation is switched on. A blocked element also loads the blower motor, which works against greater resistance and wears more quickly. Inspect the inside of the housing during replacement. If it is dusty, clean it gently before fitting the new filter. Standard and activated-carbon elements are available. The carbon version also absorbs odours and is particularly useful for vehicles driven in cities and queues.