Re: Jeff Insulate all your pipes with Armaflex insulation tubing. SR Here is a link that might be useful: ArmaFlex

First a question: is this a high efficiency furnace using 'inside' air? If so, why not just run an air supply? O.K., if you're looking for outside combustion air, look at the following link. One item works on negative pressure; the other is a passive device (no fans, etc., but relies on the weight of cooler air to shut off the supply (only vents when furnace/water heater are on). V http://www.skuttle.com/makeupcontrol.html

Some of my experiences cleaning sediment out of a hot water tank, in this case, powered by electricity: The first time was about three years ago. I started to drain the tank in preparation for replacing the burned-out lower heat element. I had attached a garden hose as most instructions tell you to do. At first the water (quite black with sediment) drained out as expected, but in a minute or two, it slowed to a trickle; I was sure the tank could not yet be empty. I soon discovered the outlet valve was plugged, and eventually removed it to get the water running again, directing it to the basement drain across a plastic sheet fashioned into a sort of trench with sides made of some short 2x4s and bricks under the plastic. The sediment came out in chunks up to 3/4" across. They were easily crumbled, but nevertheless had been solid enough to impede water flow through the valve. I reattached the valve, but felt that wasn't good enough. Following some advice from somewhere on the web, I purchased a brass nipple and ball valve from a local plumbing store and installed them to replace the original plastic valve. The inner diameter was now larger and without bends, so less likely to clog. That helped quite a lot. Meanwhile I had removed the old element. So I had an extra access hole available. I rigged up a piece of 1" plastic pipe to the end of my shop-vac hose and was able to insert that into the element hole and pull out a substantial amount of sediment. I also was able to insert a garden hose into the same element hole and flush out more sediment through the new valve outlet. I'm sure I never got it completely clean, but at least the escaping water was now clean and running freely. I installed the new heat element, and all has been fine since then, except of course, I would like to be able to do a proper regular cleaning without removing that heat element. Since that time, I have tried to remember to flush out the tank every six months or so. It hasn't been completely satisfactory, but I think if it's done regularly, at least the build-up won't be too great. Just today, I had some trouble even with that better brass valve. It became clogged as the other one had before. This time I found a good remedy in a length of 3-wire 10-gauge soft-coated electrical cable. It seemed to have just the right amount of flexibility and stiffness. Poking that through the valve and into the tank removed the obstacle. I'm thinking that for my next cleaning, I will try to attach a piece of narrow tubing to the end of a garden hose and push it into the outlet valve to do some back-flushing. At least I'm lucky in a way to have an old unfinished basement with a concrete floor and a big drain hole. Spills are not much of a problem. I'm very happy too with my makeshift "trench" which works very well to take the outflowing water to the drain. It cannot clog like a hose, and I'm even able to make a dam to catch the sediment by means of a simple fold in the plastic sheet.

Thanks both - for your comments. I'm going to remove the covering at the Water Meter end; and then attempt to blow out any existing water with compressed air. (Have some towels at the access door.) I don't think that will actually work very well, because of the length of run, etc.; but it is extremely difficult to even run the cotton string up the length to 'wick water' out. I will then seal it up with low expansion foam. My wife & I believe it is probably collecting from the downdraft in the wall... I would like to create a drain point in the pipe. Would not be that hard to do. But this would not work out well at all. We already had water coming in once - after a week of hard rain - when the ground was SOAKED - so if I create an opening at the bottom of the pipe - put in some gravel and all - the opening itself would be a problem - after a lot of rain. Thanks again. Any other thoughts or observations - are welcome.