Yet another mystery leak post

[mwmosser]

Hello all -

I have a small leak somewhere, and it's making me crazy. Our water meter is showing that about 6-7 gallons of water are flowing out every hour, even with no taps open anywhere. I have turned off the main valve to the house and the meter leak detecting triangle stops spinning, so I know there is an issue.

Here's what I have done so far:

- replaced one flapper on toilet after dye test. No change in meter spinning.
- turned off in-house valves (under all sinks and washing machine). No change in meter spinning.
- turned off valves to all toilets. No change in meter spinning.

6-7 gallons per hour is more than 1.5 cups of water flowing out every minute. You'd think that I'd hear that in the pipes, or in some fixture leaking, but there is no sound anywhere in the house. This is leading me to suspect that I have a leak outside in a sprinkler line, or (worst case) in the slab. But I don't see any weeping from the slab anywhere, and I don't see any obvious wet spots on the lawn. The sprinklers are also turned off, and the sprinkler control valves have been turned off (knife valves). Still the water meter spins.

This is a small leak, but Austin has a tiered system for water billing and this leak is putting me into a higher tier. We're a small family of three and generally pretty efficient in our water use - under 100 gallons/day. This leak is putting us into the 200+ gallon/day bracket and it's really bothersome. I hate wasting water, and even though it's only about $25 extra a month, I don't like literally pouring money down the drain either.

Any advice? I don't want to spend $1000 on a sonar leak detection service quite yet, but being unable to find the leak myself is very vexing.

thanks -

Michael M

 

[heybeats]

I had this happen, but I had poly b pipes that was on its last leg and I was in the middle of repiping my house anyway. My water pipes ran under the slab for the tenant suite and the rest upstairs. One indicator I had was my water heater was constantly running for a couple of days and I was trying to figure out why (I had installed a new water heater). I suspected it was the hot water line as it was problematic in the past. So I cut the line and installed a shut off so that it shut water off to the pipe going to the slab. My water meter stopped running.

Care to share, what kind of pipes you have? Do you know how many of our pipes run under the slab (if they are feeding to the ground/basement fixtures)? Does your water heater constantly run? If your pipe runs under the slab, do you have access to cut a portion and install a shut off so that you can isolate that line?

 

[Sponsor]

 

[Sylvan]

I would strongly suggest you shut the water supply to your toilets and note the water level. Before using it again check the level as many times the culprit is the toilet seeping and goes unnoticed

 

[mwmosser]

I would strongly suggest you shut the water supply to your toilets and note the water level. Before using it again check the level as many times the culprit is the toilet seeping and goes unnoticed

I'm going to do this with the one older (2012) American Standard toilet we have. That's the one I replaced the flapper. The other two are Toto Eco Drake toilets that I love and that don't leak a drop.

Question though: I turned off the water supply to all toilets yesterday for 2 hours and the meter still spun. No water flowing in to any toilet and the meter still spinning tells me the leak is happening somewhere other than the toilets, right?

 

[mwmosser]

I had this happen, but I had poly b pipes that was on its last leg and I was in the middle of repiping my house anyway. My water pipes ran under the slab for the tenant suite and the rest upstairs. One indicator I had was my water heater was constantly running for a couple of days and I was trying to figure out why (I had installed a new water heater). I suspected it was the hot water line as it was problematic in the past. So I cut the line and installed a shut off so that it shut water off to the pipe going to the slab. My water meter stopped running.

Care to share, what kind of pipes you have? Do you know how many of our pipes run under the slab (if they are feeding to the ground/basement fixtures)? Does your water heater constantly run? If your pipe runs under the slab, do you have access to cut a portion and install a shut off so that you can isolate that line?

Pipes through the slab - no idea what kind but likely whatever builder grade pipes were up to code in 1991 when the house was built. Our soil, coupled with our climate, means houses skate around on slabs down here, to the point where people water the slab in dry weather to keep them from moving too much.

Water heater replaced in Feb 2020 and the catch pan is completely dry, no leaks from the heater itself. It also does not constantly run - good State gas water heater that only runs when needed to refill. I do have a water recirculating pump (again, thanks to pipes going down from the heater on the second floor, through the slab, and back to master bathroom). But when pump is off meter still spins.

 

[Reach4]

Look at the drain line of your water softener.

Do they have swamp coolers in Austin?

Check if your RO unit is draining too much.

Turn off the main supply valve inside the house, and make sure the water meter does not move.

If main valve in the house makes the WM not move, turn off just the supply valve to the WH, and check the meter again.

 

[mwmosser]

Look at the drain line of your water softener.

Do they have swamp coolers in Austin?

Check if your RO unit is draining too much.

Turn off the main supply valve inside the house, and make sure the water meter does not move.

If main valve in the house makes the WM not move, turn off just the supply valve to the WH, and check the meter again.

Thanks for the tips. No water softener here. No swamp cooler. No reverse osmosis water softener either.

No main shutoff in houses here. Main (homeowner) shut off is outside underground, on our side of the water mater. Confirmed that when the homeowner valve is fully closed, water meter stops spinning. So it's our problem, not the city.

Will check WH supply valve now.

EDIT: turned off WH supply valve. No change in water meter spinning. Toilet supply valve on oldest toilet also off, and still no change in meter. The mystery persists.

 

[heybeats]

Pipes through the slab - no idea what kind but likely whatever builder grade pipes were up to code in 1991 when the house was built. Our soil, coupled with our climate, means houses skate around on slabs down here, to the point where people water the slab in dry weather to keep them from moving too much.

Water heater replaced in Feb 2020 and the catch pan is completely dry, no leaks from the heater itself. It also does not constantly run - good State gas water heater that only runs when needed to refill. I do have a water recirculating pump (again, thanks to pipes going down from the heater on the second floor, through the slab, and back to master bathroom). But when pump is off meter still spins.

Can you send us a picture of your pipes going under the slab? I mean, if its accessible then you can cut and fit a shut off valve and cut off supply going to the pipes under the slab. Depending on what kind of pipe you have, it could be easy to install a shut off valve, or it may need some work (ie soldering). I used sharkbite fittings when I was doing testing so I didn't have to waste my crimp rings.

Attached is what I did with my hot water line. If your water heater is not constantly running, that means the leak could likely be with your cold line.

 

[Reach4]

No main shutoff in houses here.

I think it is good practice to have one. Consider adding one. Not only would it help in this troubleshooting, it would be handy if you had an inside leak in a water line.

 

[mwmosser]

Can you send us a picture of your pipes going under the slab? I mean, if its accessible then you can cut and fit a shut off valve and cut off supply going to the pipes under the slab. Depending on what kind of pipe you have, it could be easy to install a shut off valve, or it may need some work (ie soldering). I used sharkbite fittings when I was doing testing so I didn't have to waste my crimp rings.

Attached is what I did with my hot water line. If your water heater is not constantly running, that means the leak could likely be with your cold line.
View attachment 70371

I could send a picture but we don't have anything here like what you're showing. The line literally runs underground from the street to the house, and I never see a pipe entering the slab anywhere. We have two outside faucets that come out from the slab on either side of the house, but other than that the pipes are all hidden. Pipes here go up from the middle of the slab through a kitchen wall to the central core of the house, where the water heater is located (yes, on the second floor in a dedicated closet).

 

[mwmosser]

I think it is good practice to have one. Consider adding one. Not only would it help in this troubleshooting, it would be handy if you had an inside leak in a water line.

Agreed. Would require cutting drywall where our pipes come up from the slab, which from what I can tell is in our kitchen.

 

[wwhitney]

So to be clear, your only shutoff valve for the whole house is at the curb? And when you leave that on, but shut off every other valve you can find, the meter still shows a leak?

Seems like you can't do any further non-destructive diagnosis. The leak is within the piping bounded by those valves. If you know where the water lateral enters the footprint of your house, you could dig up it just outside, and install a valve and an access box. Then that valve allow you to tell if the leak is in the water lateral outside the house, or under the house.

Cheers, Wayne

 

[heybeats]

I could send a picture but we don't have anything here like what you're showing. The line literally runs underground from the street to the house, and I never see a pipe entering the slab anywhere. We have two outside faucets that come out from the slab on either side of the house, but other than that the pipes are all hidden. Pipes here go up from the middle of the slab through a kitchen wall to the central core of the house, where the water heater is located (yes, on the second floor in a dedicated closet).

Just to show you the bigger picture, below is where the shut off is in my house. Just before the PRV. Now keep in mind that this picture was taken when I was repiping, so some things aren't secured as they should be and pipes have changed and eliminated since (poly b and the white pipes are no longer in service). Since the pipes were running under the slab, I was able to isolate them by adding a temporary shut off to see if it stopped the meter from running, my previous post shows the shut off.

But as Wayne and everyone else commented, best to install a shut off. Perhaps send us a picture so we know what kind of pipe it is.

If water isn't leaking through the walls or ceilings, it could be under the slab.

 

[mwmosser]

So to be clear, your only shutoff valve for the whole house is at the curb? And when you leave that on, but shut off every other valve you can find, the meter still shows a leak?

Seems like you can't do any further non-destructive diagnosis. The leak is within the piping bounded by those valves. If you know where the water lateral enters the footprint of your house, you could dig up it just outside, and install a valve and an access box. Then that valve allow you to tell if the leak is in the water lateral outside the house, or under the house.

Cheers, Wayne

You are correct in your summary. I have a rooter company coming tomorrow for a quick check of pipes outside - perhaps a roots have cracked a pipe in a small enough way to allow this leak to persist. I believe it has grown a bit since first noticing a year ago - then was <2 GPH and I put out of mind. Now with ~7 it's getting to the point where I want to diagnose/fix if possible.

Immediately after the homeowner shut off valve, the pipe splits off, one branch for sprinkler system and one branch for internal. I have closed valves in the irrigation control box but to no avail. I am leaning more towards slab leak. Will know more after the rooter company arrives tomorrow, I hope.

Digging, ripping up walls, that sort of thing are last resorts for me anyway. But I appreciate all the advice here.

 

[mwmosser]

Found the leak! Junction from the city to the house line had a crack due to roots from a tree nearby. Line is buried deep (2 feet) and would never have found the leak but had Rooter-Man Austin use sound probe to find. Repaired and all seems OK now. Had to spend a decent amount to find/fix it, but better to fix a small leak than a big one. Will sleep better from here on out.

 

[Sarg]

MWMOSSER >>>> Just a question out of curiosity ...... Can you get to your water heater from the other side ?

 

[Reach4]

line is buried deep (2 feet) and would never have found the leak but had Rooter-Man Austin use sound probe to find.

Tell us about that locating process. I assume you watched with great interest.

I would consider putting some copper sulfate crystals around that pipe to make roots find the area distasteful. https://www.homedepot.com/p/ZEP-32-oz-Root-Kill-ZROOT24/100074551

 

[Jeff H Young]

glad you f

Hello all -

I have a small leak somewhere, and it's making me crazy. Our water meter is showing that about 6-7 gallons of water are flowing out every hour, even with no taps open anywhere. I have turned off the main valve to the house and the meter leak detecting triangle stops spinning, so I know there is an issue.

Here's what I have done so far:

- replaced one flapper on toilet after dye test. No change in meter spinning.
- turned off in-house valves (under all sinks and washing machine). No change in meter spinning.
- turned off valves to all toilets. No change in meter spinning.

6-7 gallons per hour is more than 1.5 cups of water flowing out every minute. You'd think that I'd hear that in the pipes, or in some fixture leaking, but there is no sound anywhere in the house. This is leading me to suspect that I have a leak outside in a sprinkler line, or (worst case) in the slab. But I don't see any weeping from the slab anywhere, and I don't see any obvious wet spots on the lawn. The sprinklers are also turned off, and the sprinkler control valves have been turned off (knife valves). Still the water meter spins.

This is a small leak, but Austin has a tiered system for water billing and this leak is putting me into a higher tier. We're a small family of three and generally pretty efficient in our water use - under 100 gallons/day. This leak is putting us into the 200+ gallon/day bracket and it's really bothersome. I hate wasting water, and even though it's only about $25 extra a month, I don't like literally pouring money down the drain either.

Any advice? I don't want to spend $1000 on a sonar leak detection service quite yet, but being unable to find the leak myself is very vexing.

thanks -

Michael M

glad you figured it out but due to info provided in second sentance of your first post. Turned off main valve to house and meter stopped turning ? maybe you meant the curb stop? made it sound like there was a leak inside the building .

 

[Reach4]

glad you f

glad you figured it out but due to info provided in second sentance of your first post. Turned off main valve to house and meter stopped turning ? maybe you meant the curb stop? made it sound like there was a leak inside the building .

He has no main shutoff at the house. He only has the valve at the meter.

 

[Jeff H Young]

He has no main shutoff at the house. He only has the valve at the meter.

then i guess shutting that off was pointless