We have been hearing a slight sound of water running under our two bathroom sinks for about one week now even when everything is turned off. Of course, the sound goes away when main water to the house is shut off. The interesting development tonight is that now finally the shut off valve to just the house is no longer frozen and can be turned off to be turned off. Mysteriously, the water sounds under bathroom sinks disappears! instantly disappears! But checking the main water meter at the street, the leak detector is still spinning slowly the same as it did when there was water to the house when that valve frozen. Does that mean we have an outside leak now instead of an inside leak? I guess I should ask if that means we don't have a slab leak now but a leak somewhere in the line from street to yard? How do we find an outside leak? Thanks for any insights you can provide.

I still believe it's an underslab leak. The other valve is not completely shutting the water off, only restricting the flow enough so that the water leak can not be heard.

Hi and thanks for your reply. Is what you are saying is that the shut off valve to the house isn't making a complete seal to shut the water off to the house? Why would this be if the valve is turned completely off to the house? That doesn't seem to make any sense to me. Plus the water sound is completely gone and if it were still on just a little it would seem that after a while, some slight sound would come back. Yesterday before the house valve was found to work again, main water had been turned off for about seven hours and no sound of course. Before husband got the valve to the house to be able to be shut off, he put main water supple back on. He put water into the pool and then turned off the pool water, the sound remained gone for a couple of hours. Then when he put more water in the pool later to show me what he had gone, the sound came back before house shut of valve turned off. There does seem to be a lot of dampness around the soil of one side of the pool that shouldn't be there as yesterday the temperature was about 85 degrees and the roses are in the sun a lot of the day. So maybe we have more than one leak. But I do think there is a leak in the yard as that is where finally I am seeing some unusual moisture. The rose drip wasn't on either plus the moisture isn't around the base of the rose bushes like the drip would make it. The moisture is around side of the pool.

Gate and globe valves designs are the reason John Warren invented the Ball valve (Years ago I had heard that the inventor was a guy named Jim Ball, could be but not likely). The sound would not be noticed if there was a very slight leak through the valve, but your meter will show it. You may have more than one leak, but before you will know that you need to replace the gate valve with a ball valve, then check your meter to see if that was the only leak. All the best.

Thanks for your reply. I am still trying to understand about the shut off valve to house. If it were a ball valve and not a gate valve, would it be true that if no sound of water heard inside but leak detector allows same small movement that the leak is outside of the house? That is the one question I don't have the answer for yet. I definitely agree that we should have ball valve and not gate valve to house. And you are definitely correct that we may have more than one leak.

Yes,if you replace the gate with a ball valve and if you still hear water or see movement on the tattle tail meter gauge, you have a leak in the pipe between the meter and the ball valve at the house. Usually you will see moisture but if your soil is sand, the water will drain downward into the earth. You are wasting water if you have a leak. Here in So Cal the price of water is increasing and will continue for the forseeable future. That is one reason why there is such a cry for water saving devices and appliances.

Thank you so much for clarifying that if water supply ball valve off to house and no running water sounds heard in bathrooms, the leak would be outside the house somewhere. Wish we had a ball valve and not the gate valve shuttting off the water to house to know that for sure.

I posted this earlier, but it disappeared. With the street valve open, turn off the valve at the house. With someone watching the meter indicator(slowly turning per your previous post), open the house valve and see if the indicator speeds up. You might have 2 leaks, one on either side of the house valve.

You verify the valve is shutting off, by running the water and see if it stops.

Thank you for your replies. We will try them to see what happens. Yes, we could have two leaks! Interesting idea to turn off water to the house and then check back later for any water being able to turn on in the house.

Yea it sounds like you may have multiple leaks, usually when I have a situation such as yours to confirm that your just not hearing water rushing through pipes I will shut the water down and introduce air pressure into the system, like about 80 psi with a little pancake compressor. Then walk around the house, in your case inside and outside. If you have a leak, it will be unmistakable. It will sound like someone is blowing bubbles under your floor. This may not work outside however if your service line is real deep.

Hi, thanks for that very interesting idea. We have an air compressor if that is the device to apply the 80 psi. But how do you get the compressed air from compressor into the inside water pipe line? That I do not understand how to try to do.

Use a pressure test adapter fitting(make sure you get one with a gauge that will read at least 100psi).
Either remove a hose bib(if it's threaded to the house piping) and screw the test fitting in it's place, or get a hose thread female x pipe male to adapt the test fitting to the hose bib. There's a Schrader valve(fitting like a car/bike tire has) to admit the air.

Thanks for your response about the air pressure test. I thought hose bibs were on the outside water but husband explained to me that water there comes from house so great idea to test with air to help hear bubbling sound to determine if leak in the house. Where does he get step by step directions to do this test? Thanks!



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Hi and thanks for your post about trying to figure out if all house water is shut off by gate valve to house. Yes, when we turn of valve to house water and try any faucet inside, no water comes out at all and all sound is gone from the water pipes under sinks. So I am not sure what that exactly means. Someone thought house water older gate valve might still be leaking just a little bit but not enough for me to hear any sound. Someone else said to find the leak, air pressure could be apllied to the line and then leak would make easily heard bubbling sound inside house. With the fitting do you just turn air compressor on into where hose bib is to get the air into the house water system when the water is out of it? Any comments or ideas to help me isolate leak are greatly appreciated.



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As long as the hose bibb doesn't have a vacuum breaker that's a good place to inject the air. I leave the water on and set the compressor for 5 PSI above the current water pressure. The combination of air and spurting water usually makes an underground leak fairly easy to locate.

Thanks for your response clarifying that water should be left on. I am not quite sure how to tell what type of hose bib we have. Is there a way I can learn to tell which type we have? How long do we leave the air compressor on to be able to check for any bubbly noise sound if a leak inside? Again, thanks for your help!



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Thank you for all the great photos. We do not have vacuum type. I am still not sure about how to try the compressed air in the water line. One person said to do it with the water on and one said off. Maybe that means to leave the main valve on but run no water anywhere. Is that correct? How do I measure the psi of our water pressure? I know someone said to apply five pounds more than that the main water pressure. Thanks again!

The air adapter fitting I posted will show the water pressure, when it's attached to the water piping and the house shut-off valve turned on. You could then turn off the house valve and add additional pressure with the added air.

Thanks for your reply. Let's make sure I am understanding how to do this.
1. I attach the pressure gauge you posted photo of to the non-vacuum hose bib to measure our water pressure.
2. Then I apply five more pounds of air pressure with the compressor.
3. Then we all listen for bubbly noises somewhere in house to find leak.
4. If no noises heard then we turn off water to house and continue the air compressor at the what psi?



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You can't use an anti siphon(vacuum) hose bib for doing this. This procedure is what the anti siphon is used to prevent, "stuff" from back flowing into the water system.

Hi and thanks for everyone's helpful comments. Tonight husband measured our water pressure with the Schrader valve and it is 85 psi. Is that normal? Can you please advise if there are any complications that we might run into if we try adding the compressor air to our inside water line?

Please review the steps to see if correct.
1. Attach Schrader valve to hose bib, ours is NOT vacuum type.
2. Apply 90 psi compressed air to hose bib.
3. Turn off water supply to house.
4. Listen for any bubbling noises in the house to identify location of leak

What do we do next if we don't hear any bubbling noises?



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