High water usage - unvented cylinder?

[Nigel A]

Can you open up the manholes?

Have a look to see if water is flowing?

That's a good idea. I can open up and take a look. Let me check and report back!

 

[Nigel A]

Cylinder does, as in the picture above.
The UFH, boiler and related items do not, any leak there would result in the pressure dropping to zero very quickly and the boiler would stop working.


Check again - it's common for the flush mechanism to leak due to age/limescale, and the result is a thin film of water running down the back of the toilet bowl. Nearly impossible to see, but easily identified by flushing the toilet, waiting 10 minutes for the bowl to dry, and then placing a piece of toilet paper at the back of the bowl.

Thankyou for these ideas too. I will double check the toilets again, maybe even close the isolator vale for the toilets see if that stops the meter racking up

 

[kidgreen61]

Modern loos don't have an overflow, if the float valve is passing the water runs into the pan, could that be the case?

 

[oldbutnotdead]

Re the filling loop, it isn't a bad idea to disconnect one end of it- that'll tell you instantly if it's passing water (those plastic handles don't take a lot of torque before they slip on the shaft, so they look closed but aren't).
Presumably the stop tap you used which stopped the stray 44l/hr is inside the house? Just to confirm, when you turn that stoptap off your hourly consumption drops to zero.
EDIT just read more recent post re. above so you are correct, leak is not between meter and stoptap.
No outside tap halfway up the garden or anything else fed with buried pipe?

 

[MeldrewsMate]

According to Water Co.s average consumption is about 125 litre per person per day. At 328m3 per 6 months you're using about 14 people's allowance. Do you have 14 in the house?
Have you isolated the toilets, as has been suggested; even just for a few hours?
Have you a garden pond/swimming pool/lake?

The installation of the mains pressure hot water cylinder will have dispensed with your low pressure cold water tank, thereby leading to a high chance that the toilet cisterns will be overfilling and....the rest has been adequately covered by others.

 

[Nigel A]

Can you open up the manholes?

Have a look to see if water is flowing?

From having examined under the manhole, there's absolutely nothing flowing out of the waste over the space of a few minutes, I couldn't even notice a trickle. And the meter ticked up a few litres in that time.

 

[Harry Bloomfield]

Have you perhaps a garden tap left on somewhere? Are there any pipes under the ground floor which might be leaking?

If you stick your ear to a cold pipe, can you hear a flow of water?

 

[Nigel A]

Have you perhaps a garden tap left on somewhere? Are there any pipes under the ground floor which might be leaking?

If you stick your ear to a cold pipe, can you hear a flow of water?

Hi Harry B,
Thanks for the reply.
Garden taps are off. I checked yesterday to be sure.
The only pipe under the ground floor is the pipe between meter and stopcock which is one of those blue flexible synthetic pipes. It was installed at the same time as our cylinder. An given that when I close the stopcock for 30 minutes, the meter is stationary, would suggest to me that the underground pipe is fine.

I can't feel nor hear any water flowing through the main inlet pipe. Of course when I flush a toilet I can do, but that is presumably a much much higher flow than the 44l per hour trickle.

Nice choice of beer by the way

 

[Nigel A]

According to Water Co.s average consumption is about 125 litre per person per day. At 328m3 per 6 months you're using about 14 people's allowance. Do you have 14 in the house?
Have you isolated the toilets, as has been suggested; even just for a few hours?
Have you a garden pond/swimming pool/lake?

The installation of the mains pressure hot water cylinder will have dispensed with your low pressure cold water tank, thereby leading to a high chance that the toilet cisterns will be overfilling and....the rest has been adequately covered by others.

I have isolated the toilets for 30 minutes just now, and took a meter reading before and after. The difference was 23l which (almost too much so) correlates with the 44l per minimum usage that I'm seeing.

 

[Nigel A]

Meter does not increase when stopcock closed.
Meter racks up 44l per hour when stopcock turned on, even when toilet isolators are off, no taps were run, no waste going down under the manhole cover.
All external taps turned off.
Presumably if there was a 44l per hour leak in the floor between ground and first, we'd know about it!

There's no dripping from the 'overflow' from the cylinder, nor through the "tundish" (new word for me .
Is there any way that I can isolate the water from the cylinder just to check that for sure? There's two large blue stop valves, one on the top (presumably the out flow as the pipe is hot) and one on the side. Can I safely close the water going in to the cylinder to double check that nothing untoward is happening there?

The only other piping is the central heating and the underfloor heating. Presumably the heating wouldn't work if it was leaking water, and the same for the underfloor heating?

 

[BlueLoo]

From having examined under the manhole, there's absolutely nothing flowing out of the waste over the space of a few minutes, I couldn't even notice a trickle. And the meter ticked up a few litres in that time.

Have you two drains?

Fouls Sewer and Surface water?

 

[BlueLoo]

Meter does not increase when stopcock closed.
Meter racks up 44l per hour when stopcock turned on, even when toilet isolators are off, no taps were run, no waste going down under the manhole cover.
All external taps turned off.
Presumably if there was a 44l per hour leak in the floor between ground and first, we'd know about it!

There's no dripping from the 'overflow' from the cylinder, nor through the "tundish" (new word for me .
Is there any way that I can isolate the water from the cylinder just to check that for sure? There's two large blue stop valves, one on the top (presumably the out flow as the pipe is hot) and one on the side. Can I safely close the water going in to the cylinder to double check that nothing untoward is happening there?

The only other piping is the central heating and the underfloor heating. Presumably the heating wouldn't work if it was leaking water, and the same for the underfloor heating?

Can i suggest you draw out the cold water supply system.
This will help you track and trace.

Then work from the meter forwards, shutting valves and watching the meter and seeing at which point the water stops or start to flow?

 

[Nigel A]

Can i suggest you draw out the cold water supply system.
This will help you track and trace.

Then work from the meter forwards, shutting valves and watching the meter and seeing at which point the water stops or start to flow?

Hi BlueLoo,
THanks for the suggestion!
Is it safe for me to close the valves to the heating, to the underfloor heating, and to the cylinder? (I suppose so, as the stopcock has the same effect). Apologies - I'm more of a numbers person than a pipes person!
At this point I might call upon a plumber to root out the problem.

 

[Nigel A]

Have you two drains?

Fouls Sewer and Surface water?

Hmm, not sure. The literature from the survey says that our 'surface water is fed into the mains sewer'. But particularly what is connected to that I don't know (presumably the downpipes from the rainwater gutters.)
The bathroom plumbing is fed into the main waste down pipe on the side of the house which is fed down under the manhole that I inspected.

 

[Gasguru]

Don't touch any valves relating to the heating system...there's always a chance they'll leak.
If the heating system pressure is say 1 bar cold or thereabouts it is fine

Try isolating the cold main coming into the property (under the sink maybe?) and at the cylinder cold inlet to the pressure reducing valve etc.