Low water pressure after external stopcock turned on/off

Low water pressure after external stopcock turned on/off

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hairykrishna

Original Poster:

13,963 posts

218 months

Monday 4th November 2024
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Severn Trent came poking around leak finding last week. As part of the process they turned our water off for a short period. Ever since it's been back on our water pressure has been terrible. Bad enough that our combi is tripping itself off occasionally when running a hot tap.

I assumed that it was that they'd put a temporary repair in or something that was restricting flow but now they've filled their holes in and buggered off. I don't think it's air in the pipes as I've tried all taps on while I turn our internal stopcock on and off. The stopcock in the road immediately outside seems fully open, as best as I can tell.

Any ideas for other things to try? I've reported it to Severn Trent but they have a 21 day(!) response time.

The external plastic stop cock has a hex nut our side of it. Is this a filter? Or something else? I was reluctant to mess with it too much as it presumably is Severn Trent property.

My theory is that the external stopcock might be knackered and winding it in/out has left it partly closed. I'd like to be wrong though!

Immediate neighbours pressure is ok.

BenS94

3,178 posts

39 months

Monday 4th November 2024
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We had this. The guys were great - our internal stopcock had triggered the safety, but as it had been untouched for ages, had seized. They managed to free it off, turn off, then back on again, and get presto, better water pressure than ever!

hairykrishna

Original Poster:

13,963 posts

218 months

Monday 4th November 2024
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Safety? As in an anti flooding cut off or similar? We don't have one unfortunately.

OutInTheShed

11,255 posts

41 months

Monday 4th November 2024
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I had similar at a previous house.

The esteemed technicians had failed to turn the stopcock on proplerly.

hairykrishna

Original Poster:

13,963 posts

218 months

Monday 4th November 2024
quotequote all
OutInTheShed said:
I had similar at a previous house.

The esteemed technicians had failed to turn the stopcock on proplerly.
That was my first thought. It's a plastic one and it's wound all the way anti clockwise, winding it all the way the other way cuts the water off. It did look at first like a quarter turn cut off despite being about 10 turns end to end but messing about with it in various positions while my wife watched the tap made no noticeable difference.

Simpo Two

88,936 posts

280 months

Monday 4th November 2024
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I hate screw-action stopcocks; they invariably seize or fail just when you need them. If I need a water pipe open or shut I use lever ball valves.

hairykrishna

Original Poster:

13,963 posts

218 months

Sunday 24th November 2024
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Returning to this in case anyone else has the problem in future.

I determined that the flow immediately before our stopcock in the house was bad. Pressure good.

Severn Trent came out and tested the water pressure and flow at the roadside. Was good, so they basically shrugged, said it wasn't their problem. Said that it was probably the pipe from the road to the house leaking.

I pressurised the feed pipe back to the roadside stopcock with air. No leaks. Much head scratching.

Took the boundary box pipework apart. There's a very poor quality non return valve in there. Took it out. Full flow at last! Now I just need to get round to fitting a new one.




JohnnyUK

958 posts

93 months

Sunday 24th November 2024
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hairykrishna said:
Returning to this in case anyone else has the problem in future.

I determined that the flow immediately before our stopcock in the house was bad. Pressure good.

Severn Trent came out and tested the water pressure and flow at the roadside. Was good, so they basically shrugged, said it wasn't their problem. Said that it was probably the pipe from the road to the house leaking.

I pressurised the feed pipe back to the roadside stopcock with air. No leaks. Much head scratching.

Took the boundary box pipework apart. There's a very poor quality non return valve in there. Took it out. Full flow at last! Now I just need to get round to fitting a new one.
I have the same issue - tested by the water company at the end of their run in the street. I know where my water meter is - how do i id the "boundary box pipework?'


hairykrishna

Original Poster:

13,963 posts

218 months

Sunday 24th November 2024
quotequote all
The water meter is in the boundary box. The non return valve is either right next to it or, more likely, underneath. So shut off the stopcock, run a tap in the house to drain as much water as you can. Then unscrew the meter. There's then a further section than unscrews - I think a 28mm nut. The non return is the cone that's forced up into a O-ring under that nut.

OutInTheShed

11,255 posts

41 months

Monday 25th November 2024
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hairykrishna said:
The water meter is in the boundary box. The non return valve is either right next to it or, more likely, underneath. So shut off the stopcock, run a tap in the house to drain as much water as you can. Then unscrew the meter. There's then a further section than unscrews - I think a 28mm nut. The non return is the cone that's forced up into a O-ring under that nut.
Surely this stuff is 'water board property' and not something the customer should be touching?, other than to shut off the supply after the meter?

Another thing that can go wrong, many houses have a pressure regulator on the incoming main, if the waterboard has been doing work, a bit of crud can affect this.
If you've got an outdoor tap, this may be before the regulator, check for flow and pressure here?

hairykrishna

Original Poster:

13,963 posts

218 months

Monday 25th November 2024
quotequote all
I don't actually have a meter but, in my case, the non-return valve is under the place where a meter would be.

I thought that the water company owns everything up to the box. In any case Severn Trents 'engineer' said all their side was fine, must mean the valve is my responsibility...