How to ensure DSL filtering alongside an alarm

Modified on Fri, 25 Sep, 2015 at 5:12 PM

If you intend to subscribe to our fibre broadband service (FTTC*) on the same telephone line that has an alarm** fitted, then please read and act upon this article before the broadband service goes live - it will not function reliably unless the line has compatible DSL filtering in place.


We are aware that all new alarm installations must meet EN50131. We are also aware that to do this, the alarm panel must be capable of "line seizure" (for example, to dial out to Police). In order to achieve this, the alarm must be installed first in line in the system. Standard DSL filters (supplied by us and available at electronics stores) are designed to be plugged in without needing electrical skills; therefore they are not suitable for wiring into an alarm box. A specialist DSL filter, available from your alarm supplier, can be fitted to your alarm box which will comply with EN50131 (and it's derivative BS8243). We have attached details of such solutions in the accompanying files.


Please note: you must arrange supply & fitting directly with your alarm company - neither ourselves or BT OpenReach have authority (nor necessary insurance) to access your alarm box.



* Also applies to ADSL broadband services

** If you have an "alarm monitoring service" (such as Redcare) then please search for our other article entitled "Redcare" - the article above only applies to hardware alarm boxes physically fitted to the telephone line.

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