In brief
Have the condition and type of ventilation channels assessed before you agree on a cleaning. The need is not only to read the age. Filter care, use, accessibility and previous work are part of the assessment. duct cleaning is also a separate task: a maintenance of the unit does not automatically mean that the entire mains network was also handled.
This explanation is part of Ventilation.
What does the performer mean by cleaning?
Ask which feed or drain channels, branches and valves are included. Buildwise distinguishes between maintenance by the user and work on channels for which a specialised specialist is appointed. Have the method tuned to the materials present. A general amount for all channels is only comparable when it is clear which parts are available and are actually on the order.
A fabric edge doesn't tell the whole story
A visibly polluted valve may be a reason to look further, but does not prove in itself that each hidden channel has the same condition. Ask which findings underpin a proposed cleaning. Send in existing maintenance reports and tell them if they've been rebuilt. Do not allow a health guarantee or complete technical diagnosis to depend on one picture of a grate in the living room.
Discuss access before an appointment is set
Where is the unit and its inspection points accessible? Are there fixed ceilings, built-in cabinets or shared shafts? A map and some overview photos help to prepare the assignment. Do not climb into a shaft yourself to take photos. In an association of co-owners (VME), you first capture who controls access and which private and common areas are involved.
Ask how to leave the installation
Get an indication of how disassembled parts come back and how the agreed post-work operation is controlled. Ask what findings are recorded and which parts were not accessible. That makes a future maintenance decision better substantiated. A cleaning shall not leave any uncertainty about changed valve positions, disconnected connections or additional repairs that remain to be discussed separately.
Start with a review via Wattra
Send your address, device type and reason for your request: planned maintenance, visible dirt, previous renovation or modified operation. Wattra discusses a suitable assignment for your home, company or association of co-owners (VME) in Flanders. Ask for unit maintenance and duct cleaning to be clearly distinguished from each other. You don't have to choose a cleaning frequency that may not fit your installation in advance.
Sources & further reading
Official background to the technical explanation. Consulted on 18 September 2026. A manufacturer's source doesn't confirm that we supply that brand.
This is general information about electrical faults, not a diagnosis of your installation. The cause, repair options and costs require a separate assessment.
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