What we install and repair from the Dorma range
On the closer side, we cover the full TS-series — from the slimline TS-71 used on light internal doors through to the TS-83 and TS-93 specified on heavy fire-rated entrances. See commercial door closer repair and transom closer repair for the related service silos.
On the floor spring side, the BTS80, BTS84 and BTS75V are the most common cassettes we replace. The BTS75V in particular is the standard fit on retail and office entrance doors specified since the early 1990s. See floor spring repair for the work scope.
On the automatic-door side, the ED100 and ED250 swing operators are common across public buildings; we repair, service and replace these along with the associated automatic door sensors and safety scanners.
On the lock and access-control side, Dorma's SVP and similar mortice locks appear regularly on commercial doors; we cover replacements through door hardware repair.
Why Dorma is specified so heavily in the UK
Three reasons. Parts availability — Dorma maintains UK distribution depth, so universal replacement cassettes and overhead closers are usually in stock with same-day shipping. Service-life data — the TS and BTS ranges have well-documented cycle counts (typical TS-83 rated 500,000 cycles; BTS75V rated to 1,000,000 cycles), which makes specification straightforward for facilities managers.
And third, retrofitability. Dorma's replacement cassettes are explicitly designed to fit existing competitor pockets and housings, so a building fitted out 20 years ago with a different brand can be re-shod with Dorma during a planned refurb without disturbing the floor or frame structure.
Common Dorma faults we see
BTS floor springs leaking hydraulic fluid — the standard end-of-life failure mode. See leaking floor springs for the diagnosis-to-replacement walkthrough.
TS overhead closers losing closing pressure — replacement is the route once seals fail. See failed transoms.
ED automatic operators failing safety scanners or activation sensors — sensor replacement is the most common Dorma auto-door fix. See failed automatic sensors.
Mortice lock cylinders worn — we replace cylinders independently of the case where the case is sound.
Sourcing and stock
For repair and replacement work we hold common Dorma spares on the vans — BTS75V and BTS84 cassettes, TS-71/TS-83 overhead closers and springs, ED100/ED250 sensor units. Less-common parts (heritage TS-65, BTS65, ED-series electronics) come direct from dormakaba UK distribution with same-day shipping in most cases.
For specification work on new entrances we work to the architect’s or specifier’s Dorma part numbers. Where the specified part is end-of-line, we propose a like-for-like dormakaba replacement and document the swap for compliance evidence.
Maintenance recommendations
Dorma's service-life data assumes correct closing-speed adjustment throughout the working life of the closer or floor spring. A six-monthly closer adjustment on a TS-series closer extends typical service life from around 8 years to around 15 years on moderate-traffic doors. The same applies to BTS floor springs — a six-monthly check catches early-stage seal wear before it becomes a leak.
Standard door closer service contracts include the six-monthly Dorma tuning; automatic door service contracts cover ED operator and sensor calibration to manufacturer standard.