Default user 1 code is not valid?

I have recently installed a accenta g4 and on first power up I followed step by step instructions the external bell was activated and I entered the default factory user code to disarm it "Tamper Lockout" was then displayed so I entered the code again however on this occasion it said code not valid but the engineer code worked I have reset factory settings but its still saying Tamper Lockout and I cant set it or unset it?