The strangest thing is happening with my UPVC front door lock. I can't lock it (from the inside) after about 10pm at night. Yet I can lock it perfectly well the rest of the day. Has anyone experienced this with their upvc doors. Could it be heat expansion / contraction affecting the door barrell, dont know what to do really bit of a bind having to lock it from the outside and going back in through the back door.
We have a reverse effect,difficult by day.Put it down to expansion since it gets full sun.Perhaps yours is a contraction when cooling.Should be possible to adjust the hinges to alter the way it hangs.
there is usually a hole on the top of door the hinge which can be altered by an allen key. i think the middle bracket will move the door to fix this problem.