Water Leak but where?

House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Toadfish

Active Member
Joined
Feb 7, 2011
Messages
38
Reaction score
4
I got a call from a client that has a water leak on a 3 story residential home. About 2.5 gal per hour leak. I looked at the water meter and saw the flow meter turning, so I shut the main inside the house and it stopped. So no leak on the main. :) Reopen valve.

Checked and shut all of the toilet supply valves, meter still turning. No faucet, hose bib or washing machine leaks leaks. Check pop off on HWH no leaks.
No humidifiers on the hot air system. No water softener.
Listened to the PVC stacks for water running, none. The house is part on slab and part unfinished basement. No leaks seen. It doesn't appear from a visual inspection that any of the supply lines go into the slab but rather up thru the wall. So I doubt it was leaking into the slab.

I shut the main at the meter and dropped the pressure and then reopened and the flow meter is rock solid, no more water flow from flow meter. What the?

I'm scratching my head here.
 
i was scatching my head at this one too.....hey i was thinking, maybe its an underground leak. maybe from the citys piping and maybe its backing up into the house.....look forward to finding out what the prob is...please post it when you figure out what happened.post pics if you have any.kinda curious to see what kind of damage all of that water has done
 
I would have the water company change out the meter. They do go bad occasionally.

Last year, I also found I was leaking about the same amount of water from my vacation home, and could not find it anywhere. I finally had some experts come out and discovered I had a broken PVC tee fitting, right in the middle of my concrete patio slab.

In the first pic, you can see the change of color on the concrete slab, the severe cracking and the concrete falling due to the broken line. Second pic is the crack in the PVC fitting that caused all the damage. Third pic shows the slab jacked up with plumbing rerouted away from the slab, and the last pic shows the finished product, minus several thousand dollars!

I posted these pics so you can keep an open mind about what a broken line can do, and the damage it can cause.

Havasu pics (24).jpg

Havasu pics (55).jpg

Havasu pics (59).jpg

havasu pics (1).jpg
 
Last edited:
Thanks for the suggestions and input.

My next move to identify the leak source is to pressurize the system with compressed air and then use my ultrasound leak detector to search the slab.

I don't think the water lines are in the slab but not 100% sure there not. Oh yea got a call from the client, the meter is spinning again. Here's another twist according to my client there have been a few other people in the neighborhood who have seen an increase in their water bill. With the same issues.

I don't think its a bad water meter cause I can hear the water running at the main valve just can't find a leak.
 
Just a thought but check to see if you have a pressure relief valve on the system....

It will probably look something like this...

530C.jpg


Some areas use them and if the water supplier upped the pressure you'll probably have the whole neighborhood as a customer base....

They pour water down the drain without anyone knowing it's happening.

If it's what they have then install pressure reducing valves, potable water thermal expansion tanks and new T&P valves on the water heater while eliminating the relief valve and piping the gas direct to the combination gas valve.

There will be a strange valve where the T&P belongs on the water heater that shuts off the gas to the water heater. The valve will look like the one below....

210-5.jpg
 
Thanks Redwood, I'll have a look around for the relief valve. There already is a PRV on the main but the relief valve you mention makes sense. The neighborhood is 10-12 years old and I'll replaced a few PRV's already. Chance are if the relief valves are there the spring are worn out.I'll let you know what I find.
 
No luck finding either a relief valve or a leak. Drained the system and pressurized the system with air up to 100 psi and listened with no results. :confused:
 
Do you have the ability to install a gate valve between the meter and the house, so when you shut the gate valve off, your meter stops completely? This was how I was able to isolate where my leak was coming from. I went the extra effort because I was certain it was a bad meter, only to find out that my leak was under the slab.
 
A valve was already in place and that was one of the first things I did. The meter was rock solid after closing.
 
Here is a silly question but have you attempted to place a few drops of dark food coloring in the toilet tanks, to see if the water is migrating into the bowl without flushing?

Next question...T&P valves as Redwood is speaking about is on most water heaters. Did you say you had one at all, or you said you did and there was no water seepage going into the drain?

Lastly, Isolate all exterior sprinklers, if you have them. Disconnect, shut down, whatever is necessary to stop water from any irrigation.

Basically, what I am trying to do is isolate all your lines, similar to diagnosing a short in a wire, so you can fix this problem.
 
The fact that the leak is indicated intermittently on the meter rules out all the things such as leaking pipes and other leaks that won't stop.

It does leave open possibilities such as leaking toilets, relief valves, and irrigation leaks that a valve on a timer may control.
 
The fact that the leak is indicated intermittently on the meter rules out all the things such as leaking pipes and other leaks that won't stop.

It does leave open possibilities such as leaking toilets, relief valves, and irrigation leaks that a valve on a timer may control.

All the toilets are shut off, no lawn sprinklers. Relief valve on HWH was dry. If there is another relief valve buried in the wall or ceiling I couldn't find it and it didn't dump to the exterior of the house.
And having it tie into the waste line is a no no.
I would have thought after putting 100psi of air thru the system I would have been able to hear it.

I also did the dye in the tanks, no leaks.
 
Since my head is nearly bald from all the head scratching, at this time I would contact the water department. Explain all you have done and insist on a new meter. At least that would be ruled out. Since they usually have a helpful customer service department, they may also spend a bit of time to help you look in every direction possible.
 
All the toilets are shut off, no lawn sprinklers. Relief valve on HWH was dry. If there is another relief valve buried in the wall or ceiling I couldn't find it and it didn't dump to the exterior of the house.
And having it tie into the waste line is a no no.
I would have thought after putting 100psi of air thru the system I would have been able to hear it.

I also did the dye in the tanks, no leaks.

If you pressurized the system, was it holding pressure or falling?
 
If the water pressure was dropping when pressurized, there is no doubt you have a leak, and with all your snooping without locating the source, it is time to get a leak specialist out there.

It sounds like it will be either under a concrete slab or adjacent dirt, and will not go away. As a matter of fact, the leak will eventually get worse.
 
Some builders up here will tape a line to the house next door during construction, when they have built both houses, when there done with it they cap and cover it. Some smart homeowners figure this out and hook up sprinklers and such. So I really wasn,t kidding.
 

Latest posts

Back
Top