I have inherited a Veritas Home Alarm with the property I have just bought ?

Hi,

I have a Veritas Home Alarm with the property that I have just bought but the previous owners cannot remember their alarm code. I am a bit unsure whether to try the engineer code of 1234 incase it starts beeping etc.
Is there anyway, to reset the code or will I have to contact either Veritas or an electrician?

Any help would be great!