Very high water bill mystery!

[crowman]

Hi, hoping someone can help.

Recently received a water bill that was more than double the expected amount with no obvious explanation for the extra usage. Done some checks for leaks inside and out as per the water company advice but found nothing. Water company came out and did their own checks and said there was no leak and the meter was behaving as expected. However they decided to change the meter anyway as it was old. The new meter was installed yesterday at 2pm and by 8pm the reading was already 290 litres used despite no-one in the house using water and no appliances that would use any. Today at 6pm the reading has leapt to 810 litres used despite very minimal use last night and this morning only. With a volume use that high if there was an internal leak it should be obvious. The meter is specific for my house and unless someone has tapped into my supply I am puzzled how this could be happening.

Any thoughts would be appreciated.

 

[crowman]

Some meters have a little turbine wheel spinning that shows miniscule water use (that is still significant over time) and easily indicates flow long before a digit will move.

Yes my meter has little dials which the water company guy also mentioned when he looked at the meter. He said that these were how he could tell there was not even a drip out of place when he checked. I think I must have a sporadic fault which I am guessing must be in the house somewhere so will start with the above suggested tank check tonorrow.

 

[crowman]

Another thought is that 800 litres over 28 hours is about 0.5 litres / minute. If your toilet(s) have an evil American mechanism known as a 'flap valve' rather than an honest-to-goodness traditional British siphon, it's quite possible for them to quietly leak this amount into to bowl and you will only notice it if you look really carefully.

My toilet is 9 or so years old and has the siphon system. That has been checked a few times while trying to get to the bottom of the puzzle and no leaks there. As you point out with your calculations it is a high volume to be going through the meter per minute which is why I can't make out where such a lot is going!

 

[rpm]

As said already, turn both internal and external stop-cocks off, tie up the ball valve in the cold water tank AND measure the water level in the tank (either depth of water in tank or from top of tank to water level).
Then lay tissue paper around the rim of every toilet bowl and in every sink/ basin/ shower/bath waste and wait for the tissue paper to show the leakage.

 

[snowhead]

Don't think anyone has asked yet;

How old is the house?
Is your house Detached, Semi, Terrace?
Or is it part of any previously redevelopment, like Barn conversion?

If Detached are there any near neighbours?

 

[crowman]

Thanks will try this out.

As said already, turn both internal and external stop-cocks off, tie up the ball valve in the cold water tank AND measure the water level in the tank (either depth of water in tank or from top of tank to water level).
Then lay tissue paper around the rim of every toilet bowl and in every sink/ basin/ shower/bath waste and wait for the tissue paper to show the leakage.

As said already, turn both internal and external stop-cocks off, tie up the ball valve in the cold water tank AND measure the water level in the tank (either depth of water in tank or from top of tank to water level).
Then lay tissue paper around the rim of every toilet bowl and in every sink/ basin/ shower/bath waste and wait for the tissue paper to show the leakage.

 

[crowman]

The house was built in 1983 and is a semi.

 

[Joncpi]

I assume your toilet is has a close coupled cistern. It is possible for there to be a small leak from under the syphon into the bowl. This is the only place I can think of, off the top of my head, for an almost invisible leak. If you have an isolator valve on the toilet turn it off over night or alternatively tie up the ball valve. If the cistern drains over night then the problem is a leak under the syphon.

 

[rpm]

Quicker to do the tissue test Joncpi it shows the leakage up in minutes rather than hours.

 

[firemant]

Don't think anyone has asked yet;

How old is the house?
Is your house Detached, Semi, Terrace?
Or is it part of any previously redevelopment, like Barn conversion?

If Detached are there any near neighbours?

I think Snowy is alluding to the possibility that a neighbour is using your water

My thoughts were along that way,but the self emptying CWS may give the lie to that theory.

Some years ago, I had a lock up shop. During some renovations, I discover that the detached garage was wired from the flat above. The wire came from the flat, through the shop to our garage

 

[crowman]

I think Snowy is alluding to the possibility that a neighbour is using your water

My thoughts were along that way,but the self emptying CWS may give the lie to that theory.

Some years ago, I had a lock up shop. During some renovations, I discover that the detached garage was wired from the flat above. The wire came from the flat, through the shop to our garage

To be honest I thought the same at one point as I have a neighbour from he'll who also has the know how to do such a thing due to his job!

Tests suggested so far haven't discovered anything so I think I will have to get someone in to investigate further. I appreciate all the help and suggestions received.

 

[firemant]

That's fine I welcome your questions to hopefully get to the bottom of this. I had the stoptap off for about 3 hours and there was no movement. When the water company guy came he said if there was a leak he could have seen even the tiniest drip showing on the meter.

To be honest I thought the same at one point as I have a neighbour from he'll who also has the know how to do such a thing due to his job!

Tests suggested so far haven't discovered anything so I think I will have to get someone in to investigate further. I appreciate all the help and suggestions received.

Ignoring fora moment the CWS issue - If the neighbour IS using your water,it would only show movement when he is using the water. Say for an outside tap or equipment in garage.

What does CWS supply? Have you a (maybe tank fed) dishwasher and/or washing machine? Could the inlet valves on one of these be passing?

 

[crowman]

CWS is for upstairs sink, bath, shower and toilet. The downstairs sink and washing machine comes off the mains.

 

[Gasmk1]

Then your toilet is more than likely the culprit check the bowl and water will be entering the bowl when not in use

 

[firemant]

Is there an isolation valve on the WC?
If so, buy a bucket. Use the bucket for a while filled from downstairs to flush and don't use other items filled from shower. Monitor the CWS.

Or do the bog paper trick, If you haven't yet

 

[Bogart]

Some meters have a little turbine wheel spinning that shows miniscule water use (that is still significant over time) and easily indicates flow long before a digit will move.

My leak seems more obvious. With my stopcock off the little wheel still turns so my leak is between meter and stopcock. As the distance is some 30m I do not fancy digging up 30m of ground to find it, maybe in summer if we get one!
The problem quoted should be fairly easy to solve with a bit of logic as has been suggested by other contributors.

 

[Chuck]

My leak seems more obvious. With my stopcock off the little wheel still turns so my leak is between meter and stopcock. As the distance is some 30m I do not fancy digging up 30m of ground to find it, maybe in summer if we get one!
The problem quoted should be fairly easy to solve with a bit of logic as has been suggested by other contributors.

There are techniques for pin-pointing buried leaks where digging is going to be expensive, for example:

How to Find Leaks - Understanding Acoustic Leak Detection

What one often finds is that the leak is either withn a foot or so of the meter or stopcock. If not the pipe probably failed because it was an suitable type and/or was not buried correctly and so the whole lot needs to be dug up and redone properly anyway.

 

[Bogart]

Yes I was going to have a poke around the meter and pipe entry into the property. Somewhere I also have a tee off that feeds a garage and outbuildings but will start with easier ones as I know where they are.

 

[Darren Jackson]

Next time you hear your neighbour running a bath/shower,toilet flushing etc... run out to see if your meter is turning! (make sure your water is not running first).

 

[Bogart]

Nearest neighbour is 200M away highly unlikely to hear them flush the loo.