every change of tenancy requires an electrical inspection,
every cert will document the the no. of mains powered smoke detectors,
IIRC battery only complies with the some recent landlord regs but not with the building reg ?
Burglary hotspots are normally served by Yale or the local "value" alarm co.
I been knocked back on a few areas where I can't afford to live, one with keys for ragtop A5 left in the garden as they could get it started
I try to avoid speech diallers,
IIRC the last time I had the misfortune of touching a Texecom speech dailer it had all the menu's for texting but was the speech only product.
whoops...
1st I'd link loop at the pcb & check the new controls,
if the fault reappears when the loop is put back on the panel, I'd look 1st at the devices which contain isolators,
good luck
being northern & poor... a £400 intercom for people to wear out or vandalise ?
I'd use a normal intercom with a PSTN interface,
However I'd not expect a dental surgery to operate without a reception ?
consumer products - eg an IP Phone are consumer electronics..... cheap & freely available
a 0.5mm drill from screwfix is quite cheap, a medical 0.5mm drill is quite pricey...
There's different versions of same products....
If you have a picture of the PCB a popular alarm forum or whoever rebranded or manufacturered it might have be able to help