Unexplained water usage overnight ...

[SandraKJ]

Hello Everyone. I'm back! It's been a year since my original post and I still haven't managed to resolve the mysterious water usage in my home. It's driving me nuts as I just can't figure out what's going on and Thames Water aren't interested. I've attached some screenshots from over the Christmas period. I was away from Christmas Eve until the afternoon of the 27th December so there should have been no water consumption at all from 5pm on 24/12/22 until 5pm on 27/12/22. You'll see that there is a tiny amount being recorded during the afternoon/evening and I accept that I may have a small leak somewhere BUT there is a consistently large amount being used every night from 1am - 8am when I wasn't at home. The profile leads me to think that there must be something on a timer somewhere as the amount of water being "used" increases over a few hours and then tails off but I don't have anything in my home that would account for this. I was wondering if it might be a legacy issue from when the builders replaced the old back-boiler with a new Worcester Bosch combi-boiler some 10+ years ago but surely that would have all been capped off / disabled at the time. Anyone got any ideas as currently I'm "consuming" more water overnight than I actually "use" during the day. I really don't want to have to get an engineer out to investigate and to have all my lovely oak flooring ripped up in the process. Thanks for reading ...

 

[Deleted member 120897]

Have you checked the meter number against your meter number on your bill? The reason I ask is I once came across a situation where x2 flats were crossed over so one was being billed and the other rates, but the meter was recording the wrong property.

 

[SandraKJ]

You say there is no usage when off in the street, but there is usage when off at the house stopcock.
Therefore there is either a tee off before your house stopcock, or a leak between house and street, or your house stopcock doesn’t function properly.

Turn off the house stopcock and then go to each and every source of water you have and verify that they have stopped.

Report back.

Hi @Ben-gee. Thank you so much for your thoughts. I'm wondering if you might be onto something as I seem to recall when we bought the house 15 years ago that there was more than one stopcock in the house and we were told it was because one of them didn't work. The one that I can reach is under the sink and that still records water consumption overnight when the stopcock is turned off. I think from memory that the other stopcock was housed inside the chimney breast and although we could see it, we couldn't access it due to it being inside the chimney breast. I've drawn a rough outline for the downstairs of my home so you can see what I'm talking about (it's a basic diagram but you'll get the idea). There is nothing upstairs using any water as we only have a downstairs bathroom. I'm still baffled because as I've explained to other contributors, when I am away from home for any length of time, the meter accurately shows that there is no water used at any other times except overnight between 1am - 8am. So even if it's tee'd off to another property, surely I would expect to see water usage at other times of the day? If it's a leak I would have expected to see it being registered at differing times not just during a rigid 8 hour window and even if the stopcock under the sink isn't functioning properly, it doesn't change the fact that water is being "consumed" somehow, someway. Hoping this helps and I really do welcome any ideas you have about how I would go about checking if there is a tee before the stopcock in the kitchen, short of having to rip up my oak flooring? :-(

 

[SandraKJ]

Irrigation system or pond? Yours or neighbours?

Nope - nothing at all of that nature. Thanks for the suggestion though @Timmy D .

 

[SandraKJ]

Have you checked the meter number against your meter number on your bill? The reason I ask is I once came across a situation where x2 flats were crossed over so one was being billed and the other rates, but the meter was recording the wrong property.

Hi @ChrisB1982 ... yes, I've checked and the numbers match. Thanks for the suggestion though.

 

[PETE 123]

at night water pressure increases have you got a central heating sytem that needs refilling or a unvented cylinder as that may be letting bye at night when pressure higher and discharging out the safety valve.

 

[SandraKJ]

at night water pressure increases have you got a central heating sytem that needs refilling or a unvented cylinder as that may be letting bye at night when pressure higher and discharging out the safety valve.

Nope - I don't believe that's a cause as I have a Worcester Bosch Combi Boiler?

 

[PETE 123]

that would have and internal or external one maybe so could apply.

 

[SandraKJ]

that would have and internal or external one maybe so could apply.

But if that's a possibility, wouldn't I see a substantial amount of water being discharged onto the ground outside?

 

[IND_Nick]

What type of property do you have? We did a job once where a terrace house couldn't isolate their water supply from the meter tap in the road and it eventually worked out that even though they had a new separate supply for their house, mid terrace, there was an old feed under the floor from a shared supply that essentially looped into the property underthe floor(it should.of been disconnected). It could also be complete coincidence but a toilet flush is approximately 4.5 ltrs to 6ltrs and the amounts being used correspond to a number of flushes.

 

[Ben-gee]

I reckon the cat has learned to flush the loo and is absolutely loving setting his owner this conundrum.

 

[Chuck]

Along similar lines to @IND_Nick, one possibility that occurred to me was that there is a redundant connection, which should have been disconnected but was overlooked, from the property to another main. I've not come across myself but have heard 'war stories' told by others so it's an unlikely scenario but it could explain the rather strange pattern of behaviour.

If this were the case, the OPs water meter might be expected to under-read water consumption during the day so it might be interesting review the data from the water meter to see if it matches the actual consumption during the day.

 

[Deleted member 120897]

I reckon the cat has learned to flush the loo and is absolutely loving setting his owner this conundrum.

Like on Meet the Parents?

 

[MrsL6795]

Thanks @ShaunCorbs ... I've had the toilet checked by a plumber recently when I had some new radiators installed and there was no leak - also bought the dye tablets that you put in your cistern to check for any leaks overnight but there was nothing. I remain convinced that it's not a leak as I was away for 3 days with zero water usage being recorded at all during the day - just the same scenario that I've now had for 3 years where water is being "consumed between midnight and 8am. I'm baffled. Thanks for your advice as I'm sure the answer is out there somewhere.

Hi Sandra did you ever get this resolved? We have a similar issue