(097) Multipoint Lock Failing or Door Alignment ?

We often get calls from customers who have problems locking their Upvc or Composite door and to determine whether the problem is the multipoint lock or a door alignment we ask them to lock the door whilst it is open if the lock works ok then both the customer and ourselves know the problem is the alignment of the door. If the door will still not lock then its a new multipoint lock or centre case that is required.