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 hissing noise unless main water valve is shut off
Author: newyork101

Mystery noise in a one story home on concrete slab

Constant hissing sound from undected area unless the water is completely shut off in the house. Then the noise stops.

No leak detected (yet). No dampness anywhere. Just the hissing.
Cannot seem to located the exact area of the noise.
Have checked everything. Have put an ear to sinks, toilets, tubs, water heater etc.
even checked the outside spigots. Nothing found.
Plumber doesn't have a clue.

Any ideas?

About a year ago the main water line from street to house had a leak and the entire line was replaced and the new copper line was brought around the outside of the house and not under the slab. Wouldn't that eliminate the possibility of an under the slab leak?



Edited 1 times.

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 Re: hissing noise unless main water valve is shut off
Author: NICK (CA)

Did a plumber actually come out? You need to go to your water meter and see if there is movement. A plumber should be able to find what is going on.

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 Re: hissing noise unless main water valve is shut off
Author: Shoemaker2 (MA)

I would (if you haven't yet) isolate the water heater to determine if it is hot or cold. Good chance you have a leak under the slab if turning off the main make the noise stop and you haven't been able to find it elsewhere. You should also turn off the toilet stops to be sure that is not the cause. Hope for your sake it is not in the slab.

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 Re: hissing noise unless main water valve is shut off
Author: hj (AZ)

Get a plumber who DOES have a clue and knows how to diagnose whether you actually have an underslab leak, usually in the hot water piping.

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 Re: hissing noise unless main water valve is shut off
Author: pitts1975 (MS)

Plus my hot water heater is making a sound like water is running. Could someone please help me with this.The hissing sound is under my tub, and washer in the laundry room.

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 Hissing noises coming from my electric hot water heater, bath tub, and the laundry room.
Author: pitts1975 (MS)

Plus my hot water heater is making a sound like water is running. Could someone please help me with this.The hissing sound is under my tub, and washer in the laundry room.

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