Leak 1 litre per hour

Green_hopeful

We have a smart water meter.  The water company has noticed we are using a litre per hour and have suggested we have a leak. It started on 30 December 2022. I watched the meter and it looks like we are using a litre per hour when not using any water. I turned off our internal stop tap and that stopped the usage. So it looks likely we have an internal leak. I have checked the toilet cisterns and listened to try to find any dripping.  Nothing so far. I don’t think it can be a leaking pipe in the house because it’s 168 litres per week roughly so you would notice unless it’s going into the cavity under the ground floor. 

Any ideas on what to look for? I thought I might look in our sewer to see if there was water going down the sewer which might narrow the cause but other than trying to isolate areas of the house I can’t think where else to look. 

ThisIsWeird

What type of boiler do you have - heat-only or combi?

If a combi, it's theoretically possible - tho' rare (never heard of it) - for the mains water to get through to the system water via a perforated P2P exchanger, and this could make the system pressure rise to the point it opened the safety valve, and dumped the excess out the 15mm copper pipe on the outside of your house. ID that pipe, and check it's dry.

If a heat-only, then check the F&E and CWS tank overflow pipes - these are usually plastic, and stick out at soffit height. (That's if you have one or two black water tanks in the loft).

Can you lift the lids of the toilet cisterns to have a gander?

No outside tap cracked during the frosty spell?

MikeJXE

Have you checked the overflow pipes front the toilets ?

Sometimes you can get a sticking valve and water runs into the toilet that is hard to see and hear 

Annemos

Good evening. 

After my smart water meter was fitted, I checked it and noticed that the + sign was flashing, showing that some water was flowing through it. (Even though everything was turned off.)

It was indeed the toilet. I could barely see the drip, it was so small and faint. But it was using  about 238 litres in a day! A way to detect it was by putting some toilet paper at the back of the toilet above the water line to see if it stays damp. (I hope that makes sense!) 

I am also wondering... I have just had a small leak on the kitchen mixer tap. I noticed that because I kept seeing a small amount of water on the sink worktop, even though I had dried it off. There was also a damp ring underneath the tap from inside the cupboard. 


Good luck! 

outtatune

Do you have isolating valves on your various watery stuff? If so turn everything off then turn stuff on one at a time until the leak shows up again. Hopefully it's just a toilet inlet valve as that's cheap and easy to fix.

grumbler

ThisIsWeird said:

...and dumped the excess out the 15mm copper pipe on the outside of your house. ID that pipe, and check it's dry.

Safety discharge doesn't necessarily go outside. It can go to a waste pipe via an accessible and visible 'tundish'.

And I know, this is obvious, but as we know nothing about the boiler and if it's a gravity system, the overflow pipes need checking.

Green_hopeful

ThisIsWeird said:

What type of boiler do you have - heat-only or combi?

If a combi, it's theoretically possible - tho' rare (never heard of it) - for the mains water to get through to the system water via a perforated P2P exchanger, and this could make the system pressure rise to the point it opened the safety valve, and dumped the excess out the 15mm copper pipe on the outside of your house. ID that pipe, and check it's dry.

If a heat-only, then check the F&E and CWS tank overflow pipes - these are usually plastic, and stick out at soffit height. (That's if you have one or two black water tanks in the loft).

Can you lift the lids of the toilet cisterns to have a gander?

No outside tap cracked during the frosty spell?

Thank you for your comments. It is not a combi. There are tanks in the loft. I can’t see any water draining at soffit level or through the roof. We have rooms in the loft so one tank is very high in the loft. I can’t hear anything in the rooms in the loft and I can hear when we are running a shower which I suspect is cold water refilling the hot water cylinder. 

I have looked for movement in the loo water. I think you can normally see it. 

I have put a bucket under the outside tap. I could turn the stop tap off to the tap. 

Green_hopeful

MikeJXE said:

Have you checked the overflow pipes front the toilets ?

Sometimes you can get a sticking valve and water runs into the toilet that is hard to see and hear 

Will look in the cisterns of the ones we can open. 

Interestingly the one in the downstairs loo drains straight onto the floor as we found out when the ball !!!!!! stuck in lockdown one and flooded the hall. 

Green_hopeful

Sorry to amalgamate the other points. We have started looking for things that might drip intermittently eg taps and showers. We have quite a few isolation valves so might turn some off tomorrow to see if I can stop it. I have had a leak on a pressure thing which was going through a tundish in a previous house so looked for a tundish already although our loft is had to access so haven’t looked up there. 

Mutton_Geoff

If you have data pre leak then fix the leak, water companies will often give you a one off discretionary refund for the lost water. Make sure there is a corresponding reduction in your waste charge too as this is often linked directly to water consumption.

If you can't find the leak, your house insurance should cover investigation/repair.

MikeJXE

Green_hopeful said:

MikeJXE said:

Have you checked the overflow pipes front the toilets ?

Sometimes you can get a sticking valve and water runs into the toilet that is hard to see and hear 

Will look in the cisterns of the ones we can open. 

Interestingly the one in the downstairs loo drains straight onto the floor as we found out when the ball !!!!!! stuck in lockdown one and flooded the hall. 

Look in the bowl, sometimes a leak trickles down the bowl and it's hard to spot