Replacing Dsc Wls904Pl-433 Pir

British Gas installed alarm ran fine for years but recently the panel reported a trouble condition (not sure if caused by new scottish power energy meter which is also wireless).

Whilst investigating the "trouble" fault. *[2] showed an issue with zone 3. I removed the wireless PIR, checked battery and put back. Keypad then flashed up large number 3. On checking PIR appears that the tamper micro switch is now broken (switch does not spring back). This PIR is effectively a bin job right?

Where in the UK can i get a replacement at a decent price? Looks like the WS4904PW has replaced my WLS904PL-433 but are they compatiable with my system?

In the mean time is the following correct for removing the PIR from the system? And is this correct approach? I can't bypass the zone until system in ready state.

*8

Installer's Code

804 (the section for wireless programming)

3 (the subsection for zone 12)

000000 (the ESN)

## (exit programming)

will this reset any other information? i.e when i get a replacement PIR can i just do above but with correct ESN and be back to normal without any other setting changes?

thanks in advance for any help.