On 06/09/2017 18:33, jim wrote:
IIRC, enter "programming mode" & you have an hour to interfere &
change batts etc
? (with small crosshead screwdriver &
stepladder/chair:-) ).

Presumably you knew all this when you bought & installed the
wireless system?

Yes,and I change them every two years but for this one PIR which is 6
monthly, but hopefully now solved.