leaking window in a french door

I have a leaking window in a french door. The door faces west and leaks when their is a heavy rain. The leak is at the bottom of the window and runs down the door into the threshold. Can't I caulk around the glass on the outside of the door? A guy I work with said that might not work and did not say why. Thanks.

Greetings KR welcome to the Forum.

I don't know what that guy's talking about !
Sure you can Caulk the Glass.

You said that the water was running down the door, and into/thru the Threshold ?

If that's the case too, they make a strip of shaped Aluminum that you put at the bottom of the Door outside, and it sheds the water away from the Threshold.

If you've never seen one, think of a Metal Cover over a outside Door, but in miniature and it goes across the width of the door. They come in different depths, and you choose one that will drop the water sufficiently away from the door, to keep it from entering the house.

Have a good Day !
S.W.

Is the water coming in around the window and then running down the inside of the door? If this is the case then you could caulk around the outside of the window but this should only be temporary. It will eventually start to leak again and may not look very good. If the door is metal or fiberglass then the best thing would be to remove the window. The glass should be stuck to the outside Plastic frame. The inside frame has the holes for the screws and sandwich's the glass inside the door. Most door manufacturers use a double stick weather stripping to get the frame to stick to the door and act as a weather guard. I would remove that stripping and use a silicone adhesive instead. With the glass and frame out run a bead around the outside opening of the window cut out and then set the frame and glass in. Then you put the inside frame in and screw it together. If the glass is not stuck to the frame then you will need to also silicone that as well. You will need 2 people for this so the glass doesn't fall out.