The problem with the card type is that they do not provide a audable alarm just change colour which is not a lot of good if a leak is overnight whdn the cnetrak heating is running
I think that I would rather have the screaming and safe however I have not seen the booze thing
Just one tip on the boilers and again on todays snagging check on phase 3b there was no leak but the air vent was blocked
One way to tell is to make sure when you do a snagging inspection that you run the central heating, turn on all the rads, and then run taps in the kitchen and bathroom and listen to the boiler
If you can hear the boiler struggling and not running continually, almost what I would describe as a clonking noise from the boiler, there is a problem
The vents can sometimes be blocked with builders rubble which means they will run OK untill they are put under some load when they struggle
The person that we were checking for were staying in phase 3a and were having the same problem plus a number of leaking radiators so you should always check the heating and AC as part of the first inspection if the utilities are connected