We're on the last property on a shared system. The cold water pressure has never been brilliant but most days the upstairs shower would work fine. Recently the pressure has fallen to the point I can just put my finger under the tap and stop the flow, the flow rate is also low.
Next door, which is downstream, is fine and our problem exists even when they are not using any water.
The internal stop tap is fully open. The house and external plumbing will be fairly old.
Corrosion? How best to tell if there is a leak between next door and here?
A simple check would be to use a sound pole like the water company engineers use. Basically a log rod that you press one end on your stop-c*ck and rest the other end on your ear. If there is no water being used in your home and there is a leak upstream then you will hear a 'shhhh' sound coming up the pole indicating escaping water. The rod can then be used outside the home and testing the ground a intervals. By finding out where the noise is loudest will locate a possible underground pipe leak .
The same technique is use by engineers to check bearings but in that case the rod is often a screwdriver.
The water company may be interested since it certainly sounds like there is a leak. Can you find a way to measure the actual pressure when you have no flow? I had a somewhat similar problem; the external stop tap was leaking into the pit, and couldn't be closed. My supply was a (corroded) 15 mm copper pipe coming up through a concrete floor, so I would have had an unstoppable flood if this had failed before "my" stop tap. I ended up having a new polythene main brought in from the road. I had to pay a plumber to run my new pipe, but the water company were very happy to put in a convenient new boundary stop tap, and isolate the old supply without any charge.
might do but it shouldn't do though. ;-) Gate valves aren't meant for shutting off mains pressure water.
When you put your thumb over a tap, does the pressure build up or does it stay constant & low? If it builds up then that would suggest a partial obstruction (perhaps your external mains c*ck isn't fully open?) but it it stays low, then that's more suggestive of a leak somewhere. I'd call the water company.
The pressure is low - I can keep my finger under the tap. As I've said before it is a shared pipe (2 houses, semi-detached), I'm the last house and the first house is fine. It is then quite a way to the mains. I can't see how it can be a water company issue if next door is fine.
Well this thing is, if it was any kind of partial obstruction, the pressure would rise as an obstruction will only restict flow, not pressure.
If you pressure is genuinely persistently low now (and used to be higher in the past) it's hard to think of any cause other than a leak allowing the pressure to "blow off" somewhere. As you house isn't apparently flooding, it may be underground, hence my suggestion to contact your water company.
Well this thing is, if it was any kind of partial obstruction, the pressure would rise as an obstruction will only restict flow, not pressure.
Rereading your original post though I'm coming to the conclusion that your cold water is coming from a header tank in your loft, not from the mains. (Unless you have a mains pressure HW tank it's unusual to have a mains cold supply to your shower).
This being the case, it may well be the case that either the water level in your tank has dropped or you've got a partial obstruction somewhere in the system.
Are you comparing like with like in your neighbours house? Normally at least the kitchen sink tap would be supplied from the mains, more usually all cold taps and cisterns.
'Traditional' practice is to have kitchen cold tap mains fed & everything else from the tank agreed, but around here in many houses (mine included) all cold taps are fed from the main inc (electric) shower & WC.
I suspect Tim is right.
If its tank fed its entirely possible to get all sorts of crap in the tank.
A bit of pipe tracing is in order I think. Turn off the main stopcock. The cold tap in the kitchen should stop, the colds in the bathroom basin & bath should carry on, the WC cistern should refill after flushing & all hots should work - if you have a 'traditional' system.
No, there is no cold water header tank (except the one for the hot water system). All cold water is mains pressure fed. All hot water is at header tank pressure.
Point taken. The pipe between me and next door cannot be more than
20'. As next door's pressure is fine it is safe to assume that my pressure should be fine if all was well and they had everything off?
So I would have expected to hear water movement if there was a leak - I'm just putting a long screwdriver to the lead inlet pipe. If I just have an upstairs cold water tap on very slightly I can hear that through the screwdriver. Or would lead piping leaking underground upstream not be readily audible?
Am I not right in deducing that the problem is between me and my neighbour? And if it is then it can't be anything to do with the water board surely?
The problem is, it's hard to imagine any kind of pipe obstruction that would cause a *pressure* drop rather than just a flow restriction. To reduce pressure in a pipe you either needed a fancy springloaded pressure reducing vale or a big leak. Given the layout of the pipework and your listening, it sounds like it's unlikely to be a big leak.
What happens when you put your thumb over your neighbours tap? Does it blow with the pressure of can you just feel that it's considerably higher than yours? Have you held your thumb over your own taps long enough to establish that the pressure does (or doesn't) rise to the same sort of levels?
The only thing that really makes sense to my mind is that you just haven't given time for the pressure to rise when you've done your thumb test and that you're mistaking a flow restriction for a pressure restriction but then I'm not the man on the spot so I could be talking b*llocks. ;-)
Assuming that you find that when you wait long enough the pressure does rise, then as you say the problem almost certainly lies either in the link pipe between your properties or in you internal mains stopcock which may be partially blocked.
If it were my house I'd be looking for the master stop c*ck for both properties and shutting the water off and stripping your own mains stopcock to look for problem. If possible, I'd also test the flow with the internal stopcock fully open (or removed if faulty) to see the flow through the link pipe with a view to replacing it if necessary.
For anyone and everyone who has contributed to this thread the problem has been located and fixed.
The main stopcock is on the pavement. The houses are a block of cottages, 7 at the front and 2 blocks of 2 at right angles behind at each end.
The pipe comes past the end cottage (of the 7), past the front of my house (which is at 90deg to the road), past the adjoining neighbour and then works its way round to back of our adjoining houses feeding in near our back doors.
However, it also branches off on a 'T' before it reaches either of us to feed the old toilet blocks. This had a massive leak (5mm diam) in its 22mm copper pipe, and when that was repaired there was yet another leak, and now that is fixed one of the taps in the toilet blocks is leaking (owner has been notified).
Even so I cannot now hold my finger under the tap at all (I was able to hold it for almost a minute before either the pressure built up or my finger got tired).
My next door neighbour, who is upstream, was less affected because his shower is tank fed, whereas ours is pressure fed.
The water board fixed the leaks for free but as it is the second time they have been out apparently to the same 2 metre stretch of pipe I suspect they won't do it again without charging.
I've had a rough estimate of £1,000 - £1,200 if I want my own dedicated feed back to the mains. Does that cost sound about right?
That's interesting... We've got one on the mains supply going into our sealed cylinder and indeed the only time I tried to close I found it was stuck pretty much half open.
I shut the mains off at the main stopcock in the end so didn't dwell too long on it however is it something that can be cured? What is about them that fails?
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.