Continuous water noise greenstar but no leak

[coolhands]

I have a Greenstar 25si Worcester. Both the hot water and heating work ok. The problem (just occurred) is I have a continuous running water noise most apparent from the hot water (taps) outlet pipe under the boiler. I eventually traced it to that using long screwdriver to ear.

When I shut the cold water inlet valve off on the boiler, the noise stops. There is no sign of leaks anywhere that I can see or detect. I’ve shut both toilets off etc so definitely not cisterns. All taps ok. Pipework underneath bath and to shower seems ok (no leaks). I can’t find a leak anywhere.

am I right to assume the leak must be on the hot water side somewhere in my house? I assume under the floor somewhere. The noise has stopped with the valve closed and I can still use all my cold taps.

 

[terryplumb]

Do you have a water meter ?

 

[coolhands]

Yes. It is creeping round all the time when I had a look yesterday. The little cog is spinning.

 

[terryplumb]

If you turn off the cold feed into the boiler ,so no hot water comes out ,does meter still spin ? If it doesnt ,then there
Is a leak on the hot water circuit.

 

[coolhands]

Yes I’ve just confirmed if I turn cold feed at boiler back on meter starts turning.

cant understand why suddenly spring a leak from a pipe! Nothing has changed. All taps and visible pipework is ok. I guess floor is going to have to come up, I will start with kitchen (boiler in kitchen as well as main cold water into the house under sink). Tiled floor!

 

[terryplumb]

If you turn off the cold feed into the boiler ,so no hot water comes out ,does meter still spin ? If it doesnt ,then there
Is a leak on the hot water circuit.

Read the above again ,does meter spin when the cold feed to boiler is OFF.
In this position no hot water would exit boiler into hot water distribution Pipework ,but all cold pipework would still give water.

 

[coolhands]

Well for anyone searching in the future it was indeed a leak from the domestic hot water pipe going to the kitchen tap from the boiler. As it was under the floor couldn’t actually see the precise area. Cut both ends and bypassed with new pipe. It seems likely it was the area under a screeded section ie copper through cement screed (as it had a kitchen extension). So might have reacted and caused pin hole.

 

[ianmcd]

Thanks for updating, not many do, yes copper pipe if not wrap protected in screed will pinhole