Help, water leak. Any Thames water gurus here?

Just had a letter from Thames water telling me I have a leak.  They changed our meter at the start of July and bill for the previous 6 months was £880 compared to a usual of ~£250. This seems to be down to the reading on the old meter. I guess this has triggered the letter.

Thames are closed now but I’ll call at 0800 Monday and arrange an appointment for them to come and check for this leak.

I’ll also take daily meter readings in the mean time.

They say the leak is 51 litres per hour.  That seems a lot,  I can’t believe I hedge no sign of a leak like that.  No water on the lawn,  the drive,  no damp walls inside the house.   Surely even if it was inside the house, beneath the floor,  before the stopcock, at 51 litres per hour there would be very evident damp wouldn’t there?

Life has been stressful enough recently and I’m trying not to worry but mind is racing to worst case scenarios,  so I’m looking for some reassurance and logic.

If I could access the body of the stopcock in the kitchen I would shut the supply at the meter,  disconnect the stop cock in the kitchen and watch the water level in the pipe.   However I can’t,  the plumbing is neatly behind a kitchen unit with just a ~30mm hole for the tap shaft to poke through. If I try a similar test on some accessible plumbing post the stop cock,  ie the bathroom sink supply,  it won’t do anything will it? The stop cock should stop back flow should it not?

Any other ideas?

Worrying.  Meter says I’ve used 106 litres in an hour.   All we’ve done is make a few drinks.

House insurance for this sort of thing. Tracing a leak should be mentioned in your policy schedule.

There’ll be a stop tap by the meter, go and shut it off. On a recent meter it’s a black plastic quarter turn jobby.

Years ago I had a leak “somewhere under the house” where an old ran.  The meter is 70m away from the house so could have been almost anywhere!

We took a guess and bypassed one piece of pipework and that did the trick…. There was absolutely no sign of a leak on the ground.

I wish you luck.

Where is the meter in relation to the house?

Turn off the rising main in the house and see what happens – at least that will point to which side of the tap it is.

Just called insurance,  they won’t do anything until Monday when the rest of the office opens and they can check my policy.   No help there then.

If coop standard house insurance doesn’t cover track and trace… its a bit ****

Your mains water pipe is at least two feet underground. 51 litres per hour is the same as two big car wash buckets. If you’re located on free draining, geology, you’d never ever see that.

Your suggested activity won’t help you, you’re just making up things to make yourself feel better about it.

You’ve not presented any specifics about your property, or where you think your pipe runs, so it’s difficult to comment further. It could be and easy exterior fix, or you might have to abandon the existing pipe and fit a new one.

Speak to Thames water when they’re open. They may even offer some kind of detection and repair service.

There’ll be a stop tap by the meter, go and shut it off. On a recent meter it’s a black plastic quarter turn jobby.

For which you will need the right tool.

Have you got a header tank in the loft and if so where does the overflow vent to?

Can anyone one post photos for me?

The meter

https://photos.app.goo.gl/AnKyLcFmMA1Uh2J57

The green nut must be the stop,  and this plastic key…

https://photos.app.goo.gl/ctowiGV8v9z9cFi37

That fits.

It doesn’t want to turn though…. key bending.

Where is the meter? Two of our neighbours ( Severn Trent) and my father ( Southern water) have all had leaks right by the junction of the meter and the supply pipe. My dad’s was just after a meter change and all three were fixed at the water companies expense.

We, on the other hand, had a leak on a non metered joint supply, (ours got up to over 150l hour ) between the road and the property and ended up paying for it and claiming on the insurance. Galling since I had made numerous phone calls, had three site visits over nearly a year about a visible leak that Severn Trent said was a spring until they finally  fitted a temporary meter in the road to confirm. They then immediately served us with a section 75 notice to get it fixed within two weeks. This was on December 20th! We didn’t get charged for the water lost.

I’ve not seen one like that before. But it looks like you could use a hex key or a socket with extension piece on the exterior of it.

Just turned off water at kitchen cock, I’ll check in 10 mins to see if meter still going up.   That would tell me if leak before or after kitchen cock.

The house is south London,  heavy London clay soil. Typical 30s build semi.  Meter in pavement,  lead pipe under front lawn which is a bit over a cars length. Pipe emerges up above the oversite beneath the suspended floor a few feet inside the house wall under the lounge (deadly laid parquet for me ~10 years ago,  I’ve not been under since but this is how it is/ was)  the lead pipe comes out under hall and here, about 12 years ago,  I had a plumber remove the lead from then on so it’s joined with one of those compression fittings to copper.   Obviously that is my first place to rip boards up.

Before I do I’ll buy a snake camera I think….

A builders bucket is 3 gallon. Or 14 litres. So 106 litres per hour is 7.5 buckets.

If they have just changed the meter and it wasnt leaking before then i would say they haven’t done the job properly.

Meter still going so leak must be between kitchen cock and meter in the street

235 litres in 2 hours

according to the bill and reading on the old meter,  it had been leaking.  The usage for first 6 months of the year was 4.5 times normal. 

Accidentally italic

I meant to add above that claiming on the insurance was very straightforward initially but the increase in premiums post  event has been dramatic and if it happened again I think I would explore alternative arrangements first especially as ours was a visible exit of water and the guy who did the repair found it and fixed it within a couple of hours. The Severn Trent engineers had failed to find it in three visits.

Edit: If you turn the stopcock back on and place a screwdriver or similar to it and your ear on the end of that can you hear anything? Might just give you some idea if it is close to the tap?

Thames water for us too, we ended being charged over £2k on top of normal , but the huge extra was kind of good because no one could argue that we’re using so much . It was the junction of the new meter and old pipe work. Similar to OP there was no sign of water anywhere, assume it just soaked away.

As I said science officer, I’ll call Thames when they open Monday.  The letter says they can help find the leak.

Fixing the leak is the cheap bit.   I’m concerned it’s under house, been seeping years,  and caused rotten joists.   That is worst case I know, but even getting the floor up in the lounge if that’s where the leak is will destroy 50m² of parquet.

Balls.

You’ve got damp proofing, no?

You could try a socket (with extension bar) on the green hex part, if you had one long enough, just don’t force it, speak with local water utilities, although sounds like it’s a Monday response.

120 litres is only 2 l/min, slow tap. So July meter, say 6 weeks x 7 days = 42 days x number of people at house x 150L average usage, roughly 2 people, but yes check overflows, although you’ve said when you stop the kitchen stop tap the meter still spins.

If you know the route of the pipe from meter under lawn, may be easier to dig there first (helps if you can turn stop-tap off at meter) and then work out if leak is meter side or house side, so at least you know if work opening up floor inside house.

I’m concerned it’s under house, been seeping years, and caused rotten joists. That is worst case I know, but even getting the floor up in the lounge if that’s where the leak is will destroy 50m² of parquet.

You just need to weigh these costs against installing a brand new line and abandoning the old.

Oh and BTW scienceofficer, I’ve seen Thames water look for a homeowner side leak at my parents some 15 years ago,  he did just what I said in my op.

The outcome will be the same. You already know you’ve got a leak below ground between the meter and the stopcock.

.17mm socket and long extension bar freed the cock at the meter, it was just hard open.  It’s now shut…. i’ll check reading again in a few minutes but I could hear the hiss as I closed the cock so water was flowing.

Meter in pavement, lead pipe under front lawn which is a bit over a cars length.

Holy crap!

The 19th century have called to say they want their pipe back!

Get the whole lot changed for alkathene, fix your leak and improve your water flow at the same time.

Chances are they can change it over without ripping up the lounge floor.

(If that had got damp you’d know about it by now)

Great!

Yes shark bait,  lead was used well into the 20th century.  Well post war I think.

I got a plumber to take out what was easily accessible, hence why I know where the join is.  I got a plumber to do it rather than diy it just to reduce my worry over a scenario like this….. although AFAIK my previous house in Bristol where I did diy it has been fine….

Glad the flows stopped now, you can rest easy. Ok, so seeing as you’re most concerned about making it good, I’ll tell you how mine was done a couple of years ago.

insurance job. the crew weren’t interested in finding the leak (like you, it was isolated to between the meter and our stop cock), simply ‘moled’ a new plastic pipe from the front to the back of the house. Which involves digging a small trench out front, then firing a brilliant pneumatic tool to tunnel its way along the ~20m to the back of the house. Bough it up in another small trench by lifting one of the patio slabs, fitting an insulated cover where the pipe rises just above ground level, then through a hole drilled uphill through the wall to emerge under the kitchen counters. All done in less than a day, paid through insurance but I saw the invoice was about £1k.

edit: aren’t water companies providing free replacement of lead pipes into properties? Could you get a new pipe moled in under this scheme perhaps?

edit 2: I think it’s a no on free lead replacement https://www.thameswater.co.uk/help/water-and-waste-help/water-quality/lead-pipe-replacement

Thanks goldfish.

The meter hasn’t moved with the cock there shut so the vague hope of a faulty meter seems ruled out.  I’ve a leak.

I’ve ordered an endoscope from amazon which may help look under the floor but I may be lifting boards in the hall tomorrow,  where I can without costly damage.

Once I know where things stand I can think about options.   House insurance is astronomical as it is following 3 boughts of subsidence in 15 years,  so u might wish to avoid using them.   I guess I don’t mind digging up the lawn although I’ll soon change my tune there if I don’t find the leak in the first few feet!  I may speak to a plumber about how to replace the lead…..I will if it’s the lead that has sprung.  Trouble with moles is AFAIK at the moment,  to get inside the house at a place that avoids destroying the parquet the mole would have to cross the gas supply and the electric supply.

Ok I have a plan

, shut cock outside as much as possible, tomorrow I lift some floor in the hall to find the join to the old lead. I’ve ordered an Endoscope camera from amazon, if the leak isn’t under the hall I use that to search beneath the lounge. If it’s not under the house it’s under the front garden. My hope, based on the fact we can’t hear the leak, is it’s under the garden. In which case I call Thames water Monday and see what they can do. Their info says its my pipe but they may be able to help, so I ask. If the leak is under the house .. I have to decide rip up floor to fix, or reroot pipe from outside to kitchen another way, and if I claim on insurance or do myself.  Fingers crossed it’s not under the house.

Oh and a bit of trivia,  Thames water info says lead supply pipes were common until the 1970s.

Had this last year, we got a bill for about 5k so thought something was off, we’re with south west water, they sent someone out to check the leak to make sure it was our end, they checked the meter meter, then noted it was spinning like mad, and a quick once over they’d said it was on our property, they could fix it, but couldn’t detect it. I had to dig up the path, take down our lean too, and finally found the leak, they then came out and patched it and cancelled the bill.

If you’re not seeing signs of collapse/subsistence, damp, etc then it may be doing the same as our leak did, which was it found a path to the drainage and basically came out the pipe then into the drains!

Some years back one of the risers in the house sprang a leak (lead buried in modern mortar had cracked due to movement restriction). Anglian said they would be out in 6 weeks! To circumvent this I asked which contractor was replacing the local mains. Rang them and it was fixed for a reasonable £400t he next day! New pipe moled to a new stopcock under the hall floor.

If a huge delay is proposed by Thames give DOCWRA or May Gurney a ring and find out if they have a team in the area and go from there.

Thanks argee and sandwich.   At least if I end up hand digging a trench across the front garden it’s only about 10m.  I’m sure I’ll be knackered by the first metre, but it is less than it sounds like you had argee!

I’ve never noticed may guerney but used to see clancy docrwa lots.  At the far end of the street Thames have been redoing the main in the road..   only recall Thames signed vans at that.

See if you can get someone out from Thames, reality is the normal guys see this happen all the time and will help where possible, yes finding the leak is a pain, but there are companies, or equipment that can do it, our water main is at the back of the house, and goes through the garden, most of which was concrete, either the path of the base for the lean too, was a simple fix though, think Sandwich explains it best, someone comes in, traces it, then digs and fixes the pipe.

Sadly a lot of folk have old pipes running from the main to their house, they are ticking timebombs, and i believe you can get specific insurance to cover this type of event, household insurance tend to fight them a bit i hear, think ours went on about something to get out of paying anything.

After 3 bouts of subsidence I know how awful my insurers are.  Any story going to get out of a bill.   That’s where a claims adjuster working for you can help…..I may need to phone mine again.

Oh and a bit of trivia, Thames water info says lead supply pipes were common until the 1970s

Interesting and frightening!

Or house is 1950s and the pipe from the meter to the property was galvanised but had clogged up with some hard deposits. The guys who moled in my new pipe from the meter to the house cut a section out and gave it to me…. You could hardly see through it!

Yeah, it’s a nightmare for older houses, ours is plastic pipes from the main to the property, at least now i know where it all runs and the depth, but can see another repair needed over the years, so at least the concrete breaker and disc saw are sat there waiting!

If the water supplier have been upgrading the mains locally, could be there has been some fluctuation in pressure to cause failure?
Plumber friend spent a chunk of time in one village after a mains upgrade as a pressure increase had tested every weak joint in the houses.

Possible,  I do occasionally hear faint water hammer on the supply when stood by the kitchen sink and not when running water myself,  so the supply pressure fluctuates.  It isn’t the joint done 10-12 years ago to the lead though that is leaking.  I’ve now had boards up in the hall. I knew there was a reason i never finished tiling the kitchen into the hall.  No leak there.  Waiting for amazon to deliver my Endoscope and I’ll check under the lounge and back down the hall to the kitchen.

Where ever the leak is I think the fix is similar to sandwich above. New plastic pipe from the meter,  across the lawn to  beneath the study window which is easy and 8-10m.  Bring above ground there in an insulated box.  Go through the front wall just below floor level where I think it should be straightforward to poke the pipe along just beneath the floor boards and between the joists.  Poke it through about 15 feet to the hall where the existing lead finishes and I got plastic put in the rest of the way 10 or 12 years ago.

For peace of mind though,  I’m hoping the endoscope confirms the leak isn’t inside.

Amazon man came.  Ive Endoscoped 2-3m into the lounge,  dry. Endoscoped through an air brick at the front,  dry.  So pretty sure the lounge is fine.  Endoscoped a couple of m back along hall,  down through a hole just inside kitchen,  and behind the kitchen cupboard where the pipe and stop cock is,  dry.   So there are only a couple of short gaps I’ve not got to and I reckon the puddle would have easily reached where I did reach.   The house,  thankfully,  is fine.   So pressure off, the leak is under the lawn it seems.   I’ll get it fixed ASAP but I can sleep again.

I’ll phone Thames in the morning and see what they will do to help.

What a weekend.