Start with what a damper is supposed to do
A fire damper sits inside your ductwork where it passes through a fire-rated wall or floor. When a fire raises the temperature, the damper closes and seals the opening, stopping fire and smoke travelling through the ventilation system into the next compartment. That is its entire job. If it cannot close, the hole you cut through your compartment wall to run ductwork becomes an open route for fire to spread.
Under the Fire Safety (England) Regulations 2022 and the ongoing duties in the Regulatory Reform (Fire Safety) Order 2005, the responsible person has to keep this equipment in efficient working order. That is not a one-off check at installation. It is an ongoing duty, and the guidance most contractors work to — BS 9999 and the TR19 family of standards for ductwork — expects fire dampers to be tested at least annually, and drop-tested at that. The problem is that dampers fail quietly. Nobody sees them, nobody hears them, and the fault only shows up when someone finally opens the access panel.
The faults that turn up again and again
Fusible link removed, wrong, or missing. The fusible link is the small heat-sensitive element that releases the blade at a set temperature. We find links that have been snipped out during 'maintenance' to stop a damper closing accidentally, links replaced with the wrong temperature rating, and links simply absent. A damper with no link is a hole in your wall dressed up as protection.
Loose or fallen dampers. Ductwork moves, fixings loosen, and dampers that were poorly installed can drop out of the wall aperture entirely — leaving an unsealed gap. The damper might be lying in the duct, technically 'there' but doing nothing.
No access panel. You cannot test what you cannot reach. A damper installed behind a plastered wall or above a fixed ceiling with no access hatch is a common and expensive discovery. This is exactly what DW/145 addressed: dampers must be installed so they can be inspected and tested. When they are not, the responsible person inherits a compliance gap that costs money to open up.
Never tested, no record. The quiet killer. A damper that has sat untouched for a decade is not a working damper — it is an assumption.
A scenario you will recognise
A facilities manager took over a mixed-use block and inherited a maintenance file that mentioned fire dampers but held no test certificates. He commissioned a survey. Of the eighteen dampers identified on the mechanical drawings, engineers could physically reach eleven. Of those eleven, four failed the drop test — two seized with corrosion, one painted shut during a refurbishment, one with its fusible link missing. The remaining seven were behind sealed ceilings with no access at all.
He did not have a testing problem. He had an access problem, a maintenance-history problem, and a hidden-defect problem all at once. The fix involved cutting access panels, remediating the failed units, and starting a documented annual programme. None of that was visible from the corridor. All of it was his legal responsibility.
What to do about it
Start by finding out how many dampers you actually have and where they are — the mechanical drawings and O&M manuals should tell you, and if they do not, that is itself a finding. Commission a competent contractor to survey and drop-test them, and insist the report tells you which dampers could not be reached and why. That distinction matters: an untested damper is not a passed damper.
Where access panels are missing, get them installed. Where dampers have failed, fix them and keep the certificate. Then put the whole thing on an annual programme and keep the records, because under current regulation the paperwork is the proof. A damper that works but has no evidence behind it will not satisfy an inspector — and, more importantly, will not tell you whether it will still work next year.
Fire dampers fail for boring, predictable reasons. That is the good news: predictable problems can be planned out of existence.