COLD WATER SYSTEM-UNABLE TO TRACE LEAK All aspects of plumbing questions and answers, help, tips and information

[billpater]

I BECAME AWARE OF A "FLOW " NOISE COMING FROM OUR UPSTAIRS BATHROOM COLD WATER TAP. THIS WAS IN THE MIDDLE OF THE NIGHT AND ALL TANKS SHOULD HAVE BEEN FILLED UP ETC WITH NO WATER FLOWING FROM THE MAINS SUPPLY TO ANYWHERE. I WENT DOWNSTAIRS THINKING THERE MUST BE A TAP LEFT ON - I CHECKED EVERYTHING INCL WASHING MACHINE, DISHWASHER,ALL TAPS,PIPES ETC BUT NOTHING. I WENT TO THE MAINS WATER STOPCOCK AND COULD HEAR THE FLOW OF WATER COMING THROUGH- I TURNED OFF THE STOPCOCK AND THE FLOW STOPPED - WELL, MOSTLY, BUT I COULD STILL HEAR JUST A SMALL FLOW NOISE BUT HARDLY ANYTHING. I HAVE NOW BEEN DOWN BELOW THE FLOORBOARDS OF THE HOUSE BUT THERE IS NO SIGN OF ANY LEAKS AND NO WATER LYING BENEATH THE HOUSE.
SHORT OF ACTUALLY CALLING IN A PLUMBER TO INVESTIGATE WHAT I HAVE ALREADY DONE, IS THERE ANYTHING ELSE I CAN DO FIRST.
IS IT POSSIBLE TO HEAR WATER FLOWING WHEN NONE IS ACTUALLY LEAKING IN MY HOUSE - THE MAINS PIPE WHERE A BRANCH COMES OFF THE PAVEMENT TO COME INTO MY HOUSE WOULD BE AROUND 6 METRES FROM THE STOPCOCK WHERE THE WATER COMES INTO THE HOUSE- COULD I JUST BE HEARING THE FLOW FROM THE LARGE MAINS PIPE OUTSIDE THE HOUSE WHICH GOES ON THE SUPPLY ALL THE REST OF THE HOUSEHOLDS IN OUR STREET ?? THANKS - BILL
Forgot to mention that I have checked the cold water tank in the loft which feeds the hot water system and the balcock is working fine and does shut off and there is no water running out of the overflow. Also checked the supply which goes into the Central heating expansion tank - againthere is no sign of ballcock problems and no water is flowing from the over flow pipe. Additionally I have turned off the water at the mains before I go to bed, then in the morning I have checked the cold water tap in the bathroom when I get up and there is a small flow of water until in runs out in a few seconds - I would have thought that if there was indeed a leak that water would have flowed out during the night and completely have drained the cold water system - the cold water taps upstairs should just have air in them when I turn on - and have no water at all ???? :?

[nitro23456]

sure its not next door?

[f1steven]

At night there is a low demand on water and so the water pressure at everyones house is a little higher than during the morning or evening say. This extra pressure can cause the water levels in your cisterns (in the loft and the toilet) to raise somewhat . this may be the flow of water you can hear . That is why water levels should be at least an inch below overflow pipe to accommodate this rise.

[ALDA]

ARE YOU ON A WATER METER?

IF YOU ARE, YOU COULD LOOK TO SEE IF THE METER IS ADVANCING WHEN YOU ARE NOT MAKING ANY DEMAND FOR WATER.

THIS ADVANCE WOULD EITHER:-

1) INDICATE A LEAK

2) AN INCREASE IN WATER PRESSURE WHICH MIGHT BE PUSHING THE BALLCOCK VALVES OFF THE VALVE SEATS LETTING A LITTLE EXTRA WATER INTO THE TANKS AND TOILET CISTERN.

3) OR BOTH

TO FIND OUT WHICH IT IS:-

IF YOU TIE UP BALLCOCKS WITH PIECE OF STRING TO PIECE OF TIMBER RESTING ON TANK RIM OR CISTERN RIM
(THEREFORE FULLY CLOSING THE VALVES),
YOU CAN THEN LOOK TO SEE IF METER IS ADVANCING AND THIS WOULD THEN DEFINITLY INDICATE A LEAK.

[billpater]

ALDA - thanks for replying but I am not on a Water Meter. It's not a case of the tanks filling a little more than usual, ballcocks are fine----I can hear the flow any time of day- even though I haven't used any water (taps,toilet etc) for a few hours beforehand.

[billpater]

no - its not coming from next door - their house is about 10 metres away.

If it was just the cisterns that were filling up a little extra during the night then they would have to stop sometime , as they are, as the overflow is not being used and I can see where the water level always comes up to on all the tanks and cisterns - no problems there .

ANY MORE SUGGESTIONS ANYONE ????????

[nitro23456]

just a thought..... does your toilet have an overflow or does it overflow into the pan instead - thought it may just be a slight constant overflow into the pan?

[billpater]

Thanks Nitro - buy alas, NO, its not the toilet overflow pipe or overflowing into the pan---I'm stumped and i know that if i call out a professional plumber then he will just go through the same checks as I have done.

[ALDA]

YOU MIGHT HAVE A LEAK FROM UNERGROUND SUPPLY PIPE BETWEEN WATER MAIN IN STREET AND WHERE IT ENTERS YOUR HOUSE AT INTERNAL STOPCOCK.

NOT SURE IF THIS PIPE IS THE HOUSEHOLDERS RESPONSABILITY IN YOUR AREA OR IF IT IS MAINTAINED BY WATER UTILITY.

TURN OFF SUPPLY IN STREET WITH WATER KEY.

CAN YOU NOW STILL HEAR WATER RUNNING?

MIGHT IT BE DRAIN WATER YOU CAN HEAR RUNNING?

[roger196]

If the previous sensible suggestions do not work, it is time to move onto the more bizarre. Try holding a tube of rolled up paper to your ear to try and detect where the noise is coming from. This should be repeated for each room in the house. Another method is to go round the walls with a stethoscope. These are used in car maintenance to detect difficult to trace noises. One can be obtained from MachineMart or some car accessarry shops.

[Gareth Thomas]

You don't mention if you have central heating or not? How old is your house, and are the central heating pipes at any point located in the floor (Concrete)? If your pipes were not originally covered with DENSO tape or in conduit, they will have been eaten away by now with concrete. This would answer how you can hear water flowing but find no leak, because it's leaking in to the floor beneath the concrete. Don't want to sound alarmist, but this is a very common problem on old properties.

[billpater]

HI AGAIN ALDA--I WAS WONDERING IF IT MIGHT JUST BE THE NOISE OF FLOW FROM THE MAINS PIPE WHICH RUNS UP THE PAVEMENT THE WHOLE LENGTH OF OUR STREET. DONT QUITE UNDERSTAND WHAT YOU ARE GETTING AT , AS SURELY IF i TURNED OFF THE SUPPLY IN THE STREET/PAVEMENT THEN THAT WOULD MEAN THAT THERE DEFINITELY WOULDN'T BE ANY WATER FLOWING BETWEEN THE MAINS PIPE SHUTOFF AND MY INTERNAL STOPCOCK. IF THERE WAS A LEAK BETWEEN THE MAINS SHUTOFF AND MY INTERNAL STOPCOCK SURELY TURNING OFF WATER AT MAINS WOULD CURE THAT ANYWAY AND I DEFINATELY WOULDN'T HEAR WATER FLOWING ANYWAY, ?? --- ANYWAY i AM GOING TO SHUT OFF WATER AT MAINS ANYWAY JUST TO SEE IF I CAN STILL HEAR THE FLOW AT MY STOPCOCK----IS IT POSSIBLE WHAT I HAVE BEEN HEARING ALL THIS TIME AT MY STOPCOCK IS JUST THE MAINS PIPE FLOWING AND IT IS ABOUT 6 METRES AWAY - BUT OF COURSE THERE IS A PIPE COMES OFF IT AND UP TO MY STOPCOCK - I DONT ACTUALLY THINK IT COULD BE THIS BUT I'LL TRY IT ANYWAY.
IT'S DEFINITELY NOT DRAIN WATER I HEAR RUNNING.

[billpater]

[quote="roger196"]If the previous sensible suggestions do not work, it is time to move onto the more bizarre. Try holding a tube of rolled up paper to your ear to try and detect where the noise is coming from. This should be repeated for each room in the house. Another method is to go round the walls with a stethoscope. These are used in car maintenance to detect difficult to trace noises. One can be obtained from MachineMart or some car accessarry shops.[/quote]

HI ROGER-GREAT SUGGESTION ROGER - I HAVE JUST BEEN PUTING MY EAR TO THE STOPCOCK PIPE AND HEAR THE FLOW OF WATER . ALSO PUT MY EAR TO THE BATHROOM TAP AND I CAN HEAR THE FLOW -- BUT AT THE OTHER END OF THE HOUSE I CAN'T HEAR A THING IN THE KITCHEN NOR AT THE OUTSIDE TAPS. GUESS I WILL JUST HAVE TO GET IN BELOW THESE FLOORBOARDS AGAIN AND DO WHAT YOU SAY - BUT OF COURSE I HAVE SEARCHED UNDER THE HOUSE ALREADY AND THERE IS NO WATER LYING ANYWHERE . I HEAR WHAT YOU ARE SAYING RE STEPHOSCOPE - LAST RESORT I THINK. CHEERS - BILL

[billpater]

[quote="Gareth Thomas"]You don't mention if you have central heating or not? How old is your house, and are the central heating pipes at any point located in the floor (Concrete)? If your pipes were not originally covered with DENSO tape or in conduit, they will have been eaten away by now with concrete. This would answer how you can hear water flowing but find no leak, because it's leaking in to the floor beneath the concrete. Don't want to sound alarmist, but this is a very common problem on old properties.[/quote]

HI GARETH - NICE TRY - MY HOUSE WAS BUILT IN 1905 - THERE IS ABOUT 3 FT SPACE UNDER THE DOWNSTAIRS FLOORBOARD AND ALL THE PIPES ARE DOWN THERE---NO PIPES UNDER CONCRETE.. THANKS.

[htg engineer]

I would say it was just the flow of water through the mains outside - the noise will travel up the mains supplying your house.

I can hear water running sometimes, and that's just the mains water flowing - my stop tap is about 8 metres from the external mains stop tap.