The 9751 is a simple panel - doesn't do anything special so any engineer should at least be able to muddle through and work it out .

Well, its wired somewhere.

What zones are used?

eliminate them and you`ll be left with these two. (Walk testing also helps).

Then your issue is solved.

disconnect the tamper to find if thats being used?

also try disconnecting the alarm circuit from the pir and try to set should show an exit fault.

Thanks guys.

Before the 2 new PIRS were added, all zones were taken except #23 and #24. So i assumed he connected them to one of these two zones. But when i programmed these two zones into "A" setting and did a walk test, nothing registered when either PIR was triggered.

If the builder doesnt come back shortly, i'll try the tamper and also try to see where its wired into.

Thanks for your assistance.

it sounds liek hes not used the correct EOL ( if they have been fitted) and doesn't really know what hes doing.

get a qualified engineer in to look at it, shouldn't take more than an hr to find out whats wrong and sort it out ( unless hes made a complete hash of it and it needs rewiring)

good luck