In article ,
A.Lee wrote:
If the existing wiring is sound and the sensors, panel and sounder are
in the right places its a simple swap out job. Lots of similar models
on the market now so ask at your local electrical wholesale suppliers
which are readily available rather than getting a hard to source model.

No, complete rewire, so best done while doing that.
The old one is unreliable, with numerous wires going all over that
cannot be traced, so I dont really want to work on it to try and fix it
when new alarms are £100ish.

I'd point out the likely problems with wireless sensors (battery costs and
the need for regular replacements) to the owner and let him decide.

It's not difficult to trace wires with the correct equipment. Just needs a
methodical approach.

--
*Preserve wildlife - Go pickle a squirrel*

Dave Plowman London SW
To e-mail, change noise into sound.