Gardtec 360/580

[NoHow]

The alarm has eased to operate on the front door (set to zone 1). It no longer "chimes" when opened and doesn't cause the alarm to go off if opened when the alarm is set.
The back door (set to zone 2) continues to work with "chimes" and activates the alarm. I have tested the five movement sensors and they all activate the alarm.
Why would the alarm on the front door suddenly stop working? There has been no work or DIY done anywhere near the door or the alarm system.
Appreciate someone's help.
Thank you

 

[sparkymarka]

door contact stuck go and tap it see if it now chimes, replace as it will stick again.

 

[EightyTwo]

It could also be full of water...

 

[NoHow]

[iv
It has begun to work after tapping it as suggested. Thank you.

Replacing it is suggested as it will 'fail' again. Which part needs to be replaced....the wired block or the block on the door or both.

Is the wiring simple?[/i]

 

[sparkymarka]

One is only a magnet change both as it may be a different make and the magnet may not be in the same place, you will find 4 wires 2 on silver screws and 2 twisted together on a brass screw ( tamper pair) . Other types available lol