Acoustic Water Leak Detector

[jagi00]

I have a fairly heavy water leak somewhere downstream of the pump - the pump is running almost constantly but when isolated immediately downstream of the pump, it does not run so the pump controls seem OK.. Having checked all the above ground and in house possibilities several times I have been unable to locate it so it appears to be underground somewhere. Does anyone know where I could buy an acoustic leak detector or recommend someone who could locate the leak.

[Thighlander]

They don't bury water mains very deep here, if at all. How long of a run are we talking? How many units are you wasting per month. A malfunctioning toilet can use several extra per month.

[eyecatcher]

Another thing to check, does your pump directly feed a water outside or in your roof.

this time of year there is so much evapouration from water tanks that it can set off your pump every 15 minutes; telling it to keep topping up.

my first year here i was puzzled why the pump was running with no water usage and a process of logic and elimination gave me the answer.

if the pump is running constantly however it does suggest the ball cock in the wc needs adjustment or as you say a ground leak between the pump and your water outlets.

[jagi00]

They don't bury water mains very deep here, if at all. How long of a run are we talking? How many units are you wasting per month. A malfunctioning toilet can use several extra per month.

The line downstream of the pump disappears under tiles and concrete initially and splits into at least four different lines - two to inside the house and two to external circuits as far as I can tell. There are no plumbing drawings available and no easy way to isolate them other than digging up tiles and concrete then cutting and capping each line in turn but an acoustic detector should pick up the noise of the line that is flowing. All toilets etc have been thoroughly checked and are OK but my water bill has more than doubled and the pump is running almost constantly with no taps, toilets etc being used.

[HullyGully]

_{I had a similar situation, the pump was switch on and off..just for a few seconds}

_{The line leading into the garden was leaking, once repaired the pump stopped}

_{So, as you say you need to find the leak, if its possible with the 4 lines, you could pressure test each line, at least you'll know which one to dig up???}

[Thighlander]

putting concrete and tile on top of water mains is right out of the mexican plumbing playbook. Might be a good time to install separate shutoffs on each main into the house. What they are now doing in the US on residential main breaks is not even digging them up or pinpointing the leak; they just run a new one a meter to the side of the other one. Seems like this would really be easier in your case if you have the 3/4 inch PVC we had at ban wangtan, and it being under concrete. Just abandon that part of the system. If it's more than 30 THB per linear meter; I would be surprised.

[eyecatcher]

Its sound like you have done a lot of detective work already so lets go a step further; I may be stating the obvious but there maybe a few more avenues open to you.

First thing to check is the water coming into the house. Switch off the main tap, and check the water meter. Does it stop rotating if not then you problem sounds like it’s a faulty stop tap which is quite common on the older brass taps. meter..house side.

What can you see? Any stains on the walls or floors, loose wall tiles.

Outside garden, look for muddy patches or grass that is growing better than elsewhere indicating an oversupply of water.

You say you checked the toilet cistern, but are you confident water isn’t flowing out of the flap valve into the bowl. You can check this by simply putting some food colouring in the water and waiting. A suggestion but you would probably know it was the cistern as it fills up as it empties.

If you have a hot water tank/cylinder you can check the pressure relief valve. Occasionally they are plumbed directly into a drain and may be leaking without your knowledge. If you cant remove the drain pipe to check for a leak listen for a hissing sound.

Instead of trying to hunt down expensive listening equipment, first try the diy method of listening for a leak. If you have a check/service valve on your taps, bum gun, copper pipe coming from a shower boiler you can detect a leak by placing the tip of the screwdriver on the check valve, put your thumb knuckle on the handle then place the front of your ear on your thumb.

The screwdriver acts as a stethoscope and the sound of a leak transmits to your ear.

You would need to do this on several pipe runs to identify which one it may be or which appliance the leak is nearest to.

I suggest the mod moves this topic to the housing diy forum; where between us we be able help you pinpoint the leak.

[onthedarkside]

Fine - let's move to the DIY forum, with link left in CM forum

[jagi00]

OK thanks for all the suggestions guys but no joy so far. The branches downstream of the pump are all located under tiles/concrete or in the building foundations as far as I can tell so no easy way to isolate them. The Water Company has recommended someone who will take a look on Thursday - meanwhile the hunt continues....