rain leakng under UPVC front door

I had a similar problem with a porch door, about 10 years ago. What had happened was that there was a fault in the sill, caused by the factory drilling it for bottom drainage, where it shuld have drained out through the outer face. It all depends on the design of the door bottom and sill, the water that runs down the door, some of it will end up in the space under the door, and drainage has to be arranged. Of not it will get into the masonry under the sill, which is what you have got. I would get back the firm who put the door in! replaceing the cement is not the cure!! it will still get wet.

Our solution was to seal the unwanted drain holes and redrill in the correct location.

Thanks, when the rain gives up I will have a good look! I