Our house is open onto a field at the back, when it rains in at a certain angle we get rain leaking in through the top of the patio doors and into the lounge, there is no leakin or water stains in the bedroom above. We have had a roofer look at the roof which he says is fine, we have had the entire back of the house re-pointed but tonight its leaking again... pouring in, gone through 4 towels in 2hours??

You need to get new padio doors and het a new door frame

Along with better doors have you ever considered Installing a french drain. (see image) in the troubled area and simply pipe to a drainage area,
Also perhaps a home made dry well ,(see image)for those house gutters to drain into. And your thoughts? Tom

If the water is coming through the top of the door, as it appears, you may be able to install a small gable or shed roof cover that would protrude out from the wall and keep water from hitting the top of the door. This is a fairly common problem with unprotected door openings.

I agree with both of the above solutions but would like to add that if you do go for the porch cover over the doors be sure to have gutters and downspouts that are aimed away from the home and also are far enough away so that regardless of how hard it rains the water does not flow back to the house and flood the doorway.