Hot/Cold water pipe lost a little bit pressure over 4 weeks - normal?

[Daveydub]

Dōitashimashite

Had to google that!

 

[Dan Robinson]

So did I ... I can never get the end bit right .

 

[fezster]

Hi,

I have recently replaced a conventional boiler with a combi one about 2.5 months ago, and was a little bit worried about leaking when changing from low to high pressure system.

And I used the 4 weeks' of holiday to test it - by turning off the mains water supply 4 weeks ago, and check if the water from tap is as powerful as it should (what I believe is, even the mains is off, the pressure from the tap should be as powerful as usual at first instance, then reduced to some level of low pressure flow).

Unfortunately when I came back today and turned the tap with mains still off, the tap flow is already low pressure, as of about 1-1.5 seconds later from what I'd expected.

I am just wondering if anyone knows it is normal, or does it means of anywhere leaking in my house that is too little or hidden to be found?

Thanks a lot!

Regards.

I don't think you can use this method to reliably test for leaks. With a combi, the hot water is driven by mains pressure, and with the mains off, it will drip out. The fact you initially get a burst of water is not a reliable indicator of anything, as that air in the system will dissipate. Correct me if I've misunderstood what you were asking, it wasn't easy to decipher what you said.

Id say a more reliable way to test for leaks would be if you had a water meter. Make sure all your taps are off, leave your mains on, then take a water meter reading. If possible, take it an hour or so apart to see if there's a small leak. Just make sure nothing inside your house calls for water.

 

[loveextasy]

I don't think you can use this method to reliably test for leaks. With a combi, the hot water is driven by mains pressure, and with the mains off, it will drip out. The fact you initially get a burst of water is not a reliable indicator of anything, as that air in the system will dissipate. Correct me if I've misunderstood what you were asking, it wasn't easy to decipher what you said.

Id say a more reliable way to test for leaks would be if you had a water meter. Make sure all your taps are off, leave your mains on, then take a water meter reading. If possible, take it an hour or so apart to see if there's a small leak. Just make sure nothing inside your house calls for water.

Thanks for your reply and advice. What you said is exactly what I was trying to explain

I get what you mean, but unfortunately the water meter is shared with another 3 families of the terraced block. I have read some advices before for this method of leak testing but failed to find meter to my house....and my holidays just in time so I just give it a go hoping to get some rough ideas - don't have to be accurate but only an indicator if I got a leak or not...

The result seems to be good, accodring to what you have explained as well as Daveydub's. I think apart from that burst of water, everything else seems to be fine: i.e. the water seems to be run out in 10-15 seconds with the mains off which is just about right, and I guess there might be minor flow of water get into the toilet which could not be fixed (but not a leak from pipework anyway).

Anyway, thank you, and anyone else who has post their ideas/suggestions and gave me a hugh relief