Any experts on slab leaks? (Phoenix: house, floor, office)

[Voebe]

Years ago, I had a slab leak under the house - it was news to me, awful news, but I gather it's quite common in Phoenix. I got very lucky at the time. A wonderful guy at the city water department, in the leak assistance office, gave me some basic information, I found a superlative inexpensive plumber, and I found a brilliant leak detector who zoomed right in on the problem.

I now just noticed a warm spot on the kitchen floor, which was the tip-off last time, the spot near the valve where the water enters the house. This time I remembered to check the water meter, and the little triangle wasn't spinning, which would normally mean nothing is leaking. But can I trust it?

The guy at the city water department is gone and the three people I talked to now were stubbornly unhelpful, just repeating that it wasn't their responsibility, and even that wonderful plumber is gone. Could it be that in this 110-degree heat, all the water entering the house is already hot, and that's why the floor is warm? Is there something else I should check? Do any of you have a great leak detector?

[veritased]

Yes your theory is possible, I feel. My landscape guys who've been here a long time working the field told me that in the summer my cold water will run hot for quite a while, and it will be full of chlorine because it's hot from the sun/asphalt temps reaching down to the water main and actually heating up the water quite a bit. So by late in the day, if you haven't run the water, I could see the water temps in the water main rising to the point where your sensitive skin could feel a warm spot.
Makes theoretical sense, but then there are practical considerations like thickness of slab, etc.

But if the water meter was not spinning, then you can 100% sure that you are not leaking any water. Those meters really are sensitive to even slow leaks. So, again, if that water meter is not budging over a 5-10 min period, relax, you have no leak.

I wonder how they would even deal with leaks in post tensioned slabs... YIKES. Sounds like expensive repair.

[MN-Born-n-Raised]

Originally Posted by Voebe

I now just noticed a warm spot on the kitchen floor, which was the tip-off last time, the spot near the valve where the water enters the house. This time I remembered to check the water meter, and the little triangle wasn't spinning, which would normally mean nothing is leaking. But can I trust it?

Yes. You can trust the meter. You don't have a leak.