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How long does it take to completely drain out the water after the main valve in the house is shut off? Are there extra steps one should expect to do after the main water valve is shut off or turned back on?

My main water valve in the house is located in the basement. When I turn off the main water valve, water doesn't complete stop, although it runs at a very low pressure, it doesn't stop for like a good 10 minutes. Since it didn't stop, I decided not to mess with it and turned the main water valve back on. Figured I need to do more research and ask the experts here.

This is my first time trying to turn the main valve off because I'm trying to replace a toilet valve. We've been in our house just over 2 years and haven't seen any leaks or water problems, so I'm not entirely sure if this is something I'd need plumber for.

Any help is greatly appreciated. Thanks.

EDIT 6/23/23: Thank you all for the feedback so far. I still don't know what to do but I have added a picture of what my main water valve looks like. Obviously, the valve not closed in this picture.

This house does have a second floor. I believe our water is from the city pipe - there's a water meter located right in our front yard. enter image description here

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    Can you provide a picture of the valve that you shut off? It sounds likely that it might be leaky, and seeing what sort of valve and plumbing you have will be useful context.
    – Kevin Reid
    Jun 23, 2023 at 4:50
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    that would depend on the size of the home and if you have second floor.
    – Traveler
    Jun 23, 2023 at 5:06
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    I presume the "toilet valve" in question is the flush valve, so I would suggest that there's a shut off for the toilet itself located below and behind the toilet (usually on the left side as you're facing the wall) that would be easier to shut off. If it's this valve that you need to replace, then by all means, carry on with your task as planned.
    – FreeMan
    Jun 23, 2023 at 12:57
  • ...and your water supply is from? Your own private well, town or city pipes, a cistern or tank? If you have a well and shut off the valve between the well and the pressure tank, it can take quite a while to bleed off tank pressure. Normally you'd close off the valve between the tank and the house instead. And water will stay in the pipes regardless until you open valves to let the water out and air in to the pipes. But your shutoff valve could be leaky, as well...
    – Ecnerwal
    Jun 23, 2023 at 14:45
  • I would be very surprised if all water drained from the system. My house would hold water in two hot water heaters and other places, Jun 23, 2023 at 23:39

2 Answers 2

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It might take a while to drain all water pipes.

After shutting off the main valve open two faucets. One that is closest to the main valve and one that is furthest away to expedite draining. Since you do not want to drain the water heater, close it off.

When opening the main valve close the one closest to it, but leave the one furthest away open till all the air goes out. You might still have air in all other faucets so open them till air comes out.

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    Note: Since the OP is working only on the cold water side, there is no reason to open any hot water taps and drain the water heater (which will take even longer). No, you didn't suggest this, I'm just adding it as a warning for the inexperienced.
    – FreeMan
    Jun 23, 2023 at 13:03
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    I disagree, You probably don't have to drain the hot water tank, but unless you shut off the cold and/or hot water pipes into/out of the hot water tank, any fixture or section of pipe higher than the hot water tank is going to try to drain back through the hot water tank.
    – SteveSh
    Jun 23, 2023 at 20:03
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Because you haven't turned off the valve for a long time, its probably got jammed and won't quite turn over the water.

Should only take 5 minutes - or less.

Try a few anti-clockwise turns followed by clockwise turns until it turns easily.

Repeat this process annually.

Replacing this valve is a major pain, if its broken. You usually need a CO2 freezing kit.

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    Even after freeing up the valve, it may not shut off completely if it's old. Been there, done that.
    – SteveSh
    Jun 23, 2023 at 20:04

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