water running somewhere, but where???

Of all things going on right now with the bath remodel I find that I have water running somewhere. Where the water main comes into the house(near the garage) I hear a hissing(the sound of water runnig through the pipes).
1. slab home 1994
2. I checked all my connections even cut into a wall to check lines to shower - no water leaks
3. The water softener shows its in service so the split to the irrigation tells me its in the house.
4. I did find my bleed screw on the irrigation valve was leaking(so one leak solved)
5. i figured I am using 720 gallons month(2 adults and a 2.5 year old) The facsination of flushing toilets from my toddler is about 3 days old now! which isnt helping my water usage.
6. the water bill increased 5 bucks - assuming the irrigation bleed screw is the culprit for this.

So the dreaded slab leak is looming over me. Any ideas on where the water could be going before I call a plumber?

Chris

Asssuming that you're on public water, check the leak indicator on your water meter. It usually is a small triangle that spins when a faucet is open, and should not move at all when nothing is turned on.
If it is moving when everything is OFF in the house, the first place to check for hidden leaks are the toilets. Turn OFF the toilet tank shut-off valves if the meter leak indicator triangle is moving. If that stops the meter leak indicator, replace the flappers at the bottom of the toilet tanks. They usually work better by cutting out the rubber ring that slips onto the overflow pipe sticking up in the middle of the tank and using the little rubber "ears" on the flapper on the L-shaped brackets at the base of the overflow pipe.
Try to isolate the leak by turning off the valves nearesst the water main and working your way further out.
Good Luck!
Mike

leal

1. Turn off the water supply to the water heater.
2. Open a hot water faucet to be certain the valve works.
3. Listen as the sound diminishes and then stops.
4. Call your home insurance agent to see if they cover repairs from a slab leak.
5. Call a plumber.
6. He will call a leak locator, if the spot is not obvious.
7. Have the leak repaired.

This would be the normal progression since it is usually a hot water line leaking. If it is cold water, then you have to start at step #4.

thanks.
Chris

update:

Well, my bill was $23 cheaper last month than before. The only thing I did was tighten a bleed screw on a irrigation valve that was leaking pretty heavilty.
The red triangle on my street meter didnt move bit either. So I figure the hissing is coming from my water softener.

thanks again for the proper steps to find a leak.
Chris

1. make sure nothing is dripping or leaking (toilets)

2. check to see if the meter is running. In addition to the red triangle you can also read the meter, it measures down to the tenths. Note the first right hand digit, wait 5 min and see if it has turned at all.

3. If nothing is dripping and the meter runs then turn off the valve at the water heater. If the meter continues to run it is a cold water leak (assuming the valve holds 100%) If it stops you have a hot water leak (most common). To verify wait 10 min then open the valve at the heater quickly, if the hot side is leaking you will hear the pressure surge as the water runs through the valve.

When the copper under slab fails it is best to just reroute the entire hot water system. Chances are if you only fix the one leaking the other loops will fail reletively soon. It is cheaper in the long run to just reroute them all then to piecemeal them one at a time.