Bryan
This is something I\'ve been interested in too.
I\'m a selfbuilder, and (as required by our building regulations) we had to have mains-powered, interlinked smoke alarms with battery backup.
I have 4 alarms - a heat detector in the kitchen (to avoid nuisance alarms when the toast gets slightly burnt), and 3 smoke detectors in the hallways.
The heat alarm is a Kidde Fyrnetics device, like this one:
http://www.tlc-direct.co.uk/Products/KD3...9HILL.html
..and the smoke alarms are from the same series.
There is a datasheet here:
http://www.tlc-direct.co.uk/Technical/Da...223-10.pdf
I think the requirement is that they are either powered from their own circuit in the consumer unit, or from a regularly-used lighting circuit (you\'d need to check the actual requirement to be sure - you may find the latest wiring regs have changed to specify a separate circuit only).
Ours have their own circuit.
I have 2core+earth cable running from the consumer unit to the first alarm, and then the others are daisy-chained from that using 3core+earth cable, the third core being used for the interconnect.
I have been wondering how I might hook these into Comfort.
I guess when the alarms go off, there is a voltage present on the interconnect wire, that could be interfaced to a Comfort input.
But I don\'t know any details of voltage level.
Also, I\'m not sure there is a interconnect voltage standard that different manufacturers use.
By the way, they ain\'t half noisy when they all sound together !!