We have similar problems, in that our patio door leaks from the top when there's driving rain. I thought I cured it by discovering bad sealing around our bedroom window which is directly above, causing water to seep down wall cavity & leak through patio door's top join where the frame meets the interior wall. I put silicone around the bedroom window frame & it solved the problem, but it's started leaking again. Maybe wants a proper re-seal.
