Simon, in the meantime, you could connect the door contact to a 24hr/tamper zone (or to a normal zone and set system omitting all else).

Then you could follow the route of the cable as best you can, walking on it or applying pressure as you go. If the alarm activates at a certain point, check that point in the cable for damage. My bet is you'll find a staple that has damaged the cable and is causing intermittent faults.

You could also try swapping the two cores(if you have any spare) of the cable that supplies the contact. It's worth checking for damage first, though, as other cores in the cable may also be damaged.

Edited November 8, 200421 yr by Brian c

Thanks for the suggestions. I'll check the cable where I can, but I ran most of it under the floor boards when I was renovating the house 5 years ago to avoid the risk of staples, carpet grippers etc.

I'll check the cable where I can, but I ran most of it under the floor boards when I was renovating the house 5 years ago

Check for cable Gnawing then...Pesky moggies..