I finishing laying new underground PVC schedule40 in my back yard and I spent 3 full days doing it. I have a question about draining it in the winter. Even though I rented a monster trencher, I was disappointed to learn that my average depth is 15 inches. It sure looked deeper at the time. That's another story. QUESTION: Can I completely drain the pipe of water by blowing compressed air thru it, from a basement fitting, forcing water up a grade? One person even told me to blow air thru the the tiny 'waste' cap on a 'stop/waste' valve. That looks to tiny to get a high volume of compressed air thru. If this air draining works, I was thinking of using a regular air fitting to connect air to. I would like an opinion on the waste valve being used for air also. I have heard that it is a common practice to blow air to winterize, but I am not convinced that it works in my situation. An overview is that my pipe runs away from the house and uphill from the house. But here is more pipe layout detail it you need it: In my back yard, my 3/4 pvc pipe slopes from a faucet at a high grade point near the back property line, downward toward the house. A 60 foot run. It is a 3 ft drop from the high point to the low point, 60 ft away. Then, where the pipe enters the house, there is a 90 elbow in the ground such that the pipe then goes straight up the house wall 2 feet and enters the basement, where it is connected to my house main. The pipe is only buried 1 foot deep at the house end of the pipe run. I would have to blow the compressed air from the supply side in the basement, and force the water uphill thru 60 feet of pipe, and out the faucet at the other end. My concern is that I will only blow out 80 percent of the water and the 20% remaining in the pipe will rest at the lowest point in the pipe, near the house, where it will collect, filling 5 feet of pipe with water, then freeze and burst in the winter. Do you agree? I was then told that by putting a drain box and valve at the low point in the run, that it would contribute to winter problems because of the cold air at the pipe. If the line is drained of water, then isn't a valve box safe to use? Are the boxes prone to problems? Do plumbers avoid them? Mark

I had a leak from the air gap from the dishwasher all around the kitchen sink. I replaced the air gap, but water still seems to come out from all sides of the new air gap. Any ideas as to what else I should be looking at?