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View Full Version : City Water Supply to Unheated Home in Winter... concerns..


sandylulu1
Feb 24, 2015, 10:07 AM
Hi all, I am looking for some input from those smarter than I...

Here's the situation... Home is in the northeast with city water supply. Temperatures can easily be below zero for extended periods. Assume house is winterized properly and all power and heat is off for all winter months.
The city water enters the basement at just above floor level travels for 2 feet and then turns and runs vertically to another 2 feet to the meter. The water supply valve to the home is in the vertical stretch between the floor and the meter. Now obviously there will be water up to the water supply all winter long in an unheated basement. What are the chances this area will freeze up and cause problems. If so, what would be an alternative.
I realize the basement is 4-5 feet below grade, but I would have to assume it will be below freezing down there with zero degree exterior temps... no?

ebaines
Feb 24, 2015, 10:51 AM
Indeed the air temp in the basement could be below freezing, if it's cold enough outside. As the temp upstairs go down the cold air will sink into the basement, making it colder, so one thing to do is keep the basement door closed. But even if the temp gets below freezing in the basement the pipe is unlikely to freeze between the entrance and the shut-off valve, because the water in the pipe from the street that is underground will be warmer than freezing (assuming it's properly buried below the frost line). So as water in the exposed portion gets cold, it will sink back towards the underground portion and be replaced by warmer water. Hence I doubt that there will be an issue. However - better safe than sorry: you should consider shutting the water off at the street, and also consider insulating the exposed portion of pipe from the wall to the shut off valve.

sandylulu1
Feb 24, 2015, 12:07 PM
Thank you very much ebaines. Very insightful and what you say does make sense. Just thinking out loud here... If we were to shut the water off at the street there is still no way to drain the water from below the valve in the basement and the valve in the street... correct? So essentially the water in the line from the valve in the basement out to the street shut off would be trapped. When you shut the water off with the valve out towards the street that is down in the hole, there is no means I believe to drain any water there? If that's the case & what you say is correct, that may make it worse because the water can no longer mix with the warmer underground water from the street. I guess another valve could be installed in the horizontal portion of the pipe in the basement and opened after the valve at the street was closed which would allow the water to drain out of the vertical pipe in the basement and allow any water in the pipe from the street to the basement to exit via gravity because there would no longer be any pressure in that line.

joypulv
Feb 24, 2015, 12:09 PM
Why shut off all power? Is it worth it? Isn't there a small minimum you can pay for? That way you have some peace of mind for little things like a light on a timer, and a small heat wrap for that water main.

sandylulu1
Feb 24, 2015, 12:16 PM
Why shut off all power? Is it worth it? Isn't there a small minimum you can pay for? That way you have some peace of mind for little things like a light on a timer, and a small heat wrap for that water main.


Thank you joypulv. We had considered that. Our concern was not the $. Just the idea of having the power off when no one was around for a few months seemed safer that having the power on. Maybe we need to rethink?
Also,if the heat tape was essential and the difference between freezing and not freezing, we were concerned with power failures(which are not uncommon in the area) I guess though, it would be rare to have a failure for more than a few days in the winter. It might be the way to go.