Hi,

We've got a front door multi-point lock, of the "pull up to lock"
variety. Multiple bars slide across up and down the door when this is
done.

It is steadily getting harder to lock. Some real vertical force is
needed. It seems this is a long existing problem which the previous
owner neglected to fix, as the door handle itself has worked itself
slightly loose due to the forces being exerted on it.

The door locks much more easily when it is open, which would point to
an alignment/warping problem in the carpentry.

Any basic advice, other than liberal coatings of WD40 to begin
with?

(The combination of the new house, handle being loose, and locking
problems mean we are more likely to call out a locksmith to fix all of
this -- including new locks for the security aspect. What sort of
price should I be looking at, when getting quotes?)

Thanks,

Tris.