I had this happen last year. It leaked at 2 places. The first was when I was rinsing and the water jets squirted under some of the plastic covers at the top of the conservatory. This was just down to an unnatural angle, rain wouldn't have got under them but the wfp jets did. I told her it shouldn't happen but she wasn't bothered as it was built before they moved in and she didn't want to rectify it as it didn't do it while raining...fair enough. She then call me when it rained to say it was leaking. I went back and had a look and realised it was getting in where I had pulled out some old sealant/ rubber with the brush where the roof sections meet the struts. This can happen on older roofs as the rubber degrades, it pulls out easily. I was still surprised it had leaked though but just ran some sealant down it and all was fine. You could have the same problem but it could be many other things. I'm sure tHere are many on here that can advise if my suggestion isn't right for you.
