water dowm my chimney

here is the whole story

thanks so much for replying. Last year we had a back 3 season porch put in. Prior to this the exhaust for our boiler came directly out of the back side of our house. Not wanting to smell boiler exhaust on our new porch we had the chimney pipe extended to bring the exhaust up just past the edge of the roof. It was working fine for four months until i came home late one night and the house was filled with this awful smell and there was a black hazy cloud in the basement. We had the boiler cleaned in July prior to the improvement. When the tech came to fix the problem he said that the boiler was so full of soot that he cleaned it the best he could and he would have to come back in about 3 weeks to adjust something as he had to burn the rest of the soot off. He came back and said everything was fine but the same awful smell and cloud incident happened again in December. When he came back he said that the reason that this was happening was that the top of the chimney did not have a 10 foot clearance around it and that the only way to permanently fix the problem was to make it higher. Our roof is pitched at about a 45 degree angle. So we had this done in early June and every thing was fine. The tech came back to check the efficiency and said it was the highest level and that the problem with the soot that we were having should not happen again. About 3 weeks ago we noted some water on the floor after a wind driven  rain storm. At first it was just a bit but now it takes 5 bath sheets to soak up the water. We have electric hot water and since it is the summer the boiler has not been needed so it was not noted that it was not working. . This afternoon i tried to test to see if the boiler would come on by raising the temp that it would kick on to above the room temp at the time and nothing happened. I will be calling the repair tech from out oil co. on Monday but we were thinking that the cap might not be big enough. When we asked the place that the present cap was purchased from he said the one we had was the biggest and that if we wanted a bigger one we would have to have a piece welded onto the one we already had. I didn't think that was such a good idea as it might again change the way the draft operated and we would be right back were we started. These pieces of insulated pipe for this chimney are 100 dollars a foot and have become quiet an expense. The house is only 3 1/2 years old and there has always been a cap on it so i doubt that there was a blockage in the pipe.  All I wanted was a place to hang out without the bugs and enjoy my beautiful mountain view.    UGGGGGG