Water pressure issue upstairs only

[dilalio]

Thanks for all the replies so far - much appreciated.

So UU have now been and replaced the stop cock in the street...but there's no difference in the situation The water pressure in the bathroom sink tap is still very low (I just tested...28 seconds to fill a 1 litre bottle with the cold tap full on).

The bathroom fitter is now saying that he thinks it's the taps that are the problem and doesn't want to spend any more time investigating and doesn't think that "messing around with the pipes" will yield any benefit. The trouble is, I know rock all about plumbing so can't really speak with any authority at all...but to my simple mind, if the old pipes/taps had OK pressure and the new pipes/tap don't, that would indicate an issue somewhere in the new pipes/tap! That's not so unreasonable is it?

Is there anything in the possibility that because the old taps were individual (i.e. a hot tap and a cold tap) and the new tap is a mixer, it could be something to do with the mixer tap itself? From a quick Google it looks like mixer taps do need greater pressure to operate, but would the difference be that noticeable?

As the floor in the bathroom is now all laid, it's only possible to get at the pipework through the kitchen ceiling below...and as that's being replaced at the moment, it's an opportunity to get at the pipes. The fitter (who's also doing the ceiling!) is pushing to get the ceiling all done and plastered...but once that's done, if there is a problem that requires access to the pipes to resolve, it will either mean ripping up the new bathroom floor or ripping down the new kitchen ceiling...neither of which I'd like to do if at all avoidable!

Could you take some photos and upload them here. Best view of any plumbing we're likely to get is of the connections under the basin so take a couple of shots of that area.
Also, if the ceiling below is open take some of that too.
To test pressure/flow of pipework I would be looking to tap into the exposed pipework in the ceiling, at the closest point it enters the bathroom (best at the point where new pipework was joined to existing) and divert this temporarily into a bucket or outside using lengths of hep/Speedfit with some push fits and a couple of lever valves. This would show if restriction is in the new carcassing/brassware.
I may be wrong but from what I've read here, your fitter seems to be more of a builder than a plumber.. is the new pipework copper or plastic?
Whilst you have the opportunity (with the ceiling exposed) why don't you bite the bullet and get a plumber out to investigate for you?
I'd want this remedied before the lid below is closed up!

 

[HERTS P&D]

High pressure taps on a low pressure system. Change taps for the correct type. Sorted!

Andy

 

[dilalio]

High pressure taps on a low pressure system. Change taps for the correct type. Sorted!

Andy

Being a combi, it "should" "technically" be high pressure but we have no pressure flow rate data.

@slicendice did UU give you results of a pressure and flow test at their stopcock when they replaced it?

 

[HERTS P&D]

Sorry, didn't see that bit.

My next guess is a hidden faulty stopcock or gate valve.

All pipework will need to be traced back.

Andy

 

[polesapart]

Seen a similar issue where fittings had been stored jumbled up and a 10mm insert had found its way into a 15mm speedfit fitting.

As Dilalio says, Tee into the pipework and do a bucket flow test before closing the ceiling.

 

[slicendice]

OK, so bit of an update from today.

Dilalio...did what you suggested and diverted the input that was going into the tap into a bucket. As it turns out, the pressure is absolutely fine! If anything it was slightly higher than expected. So that pretty much narrows the issue down to the tap itself, as the pressure going into the tap is fine.

The tap that's fitted is (apparently) for low pressure usage, so the fitter has gone back to the supplier and asked for an explanation. I'll update once I hear what they say (though I have to admit, I just have this suspicion it could end up being a bit of a finger pointing exercise! Or am I just being cynical? ). Anyway, I'm awaiting their feedback with interest...

Interestingly enough, when the tap was reconnected again, it was even worse than before - last night I timed filling a 1 litre bottle and it took 28 seconds and it's now dropped to 45 seconds!

 

[slicendice]

@slicendice did UU give you results of a pressure and flow test at their stopcock when they replaced it?

No they didn't! They turned up and did the job and I didn't hear anything from them! Well...I'm assuming they didn't do the test, but maybe they did and just never quite got as far as telling me? Anyway, I'm going to get back to them and ask the question...

 

[HERTS P&D]

Have you checked the gauze on the tap spout?

Andy

 

[dilalio]

OK, so bit of an update from today.

Dilalio...did what you suggested and diverted the input that was going into the tap into a bucket. As it turns out, the pressure is absolutely fine! If anything it was slightly higher than expected. So that pretty much narrows the issue down to the tap itself, as the pressure going into the tap is fine.

The tap that's fitted is (apparently) for low pressure usage, so the fitter has gone back to the supplier and asked for an explanation. I'll update once I hear what they say (though I have to admit, I just have this suspicion it could end up being a bit of a finger pointing exercise! Or am I just being cynical? ). Anyway, I'm awaiting their feedback with interest...

Interestingly enough, when the tap was reconnected again, it was even worse than before - last night I timed filling a 1 litre bottle and it took 28 seconds and it's now dropped to 45 seconds!

OK. That's something. But what about the other fixtures? (shower valve, Bath filler etc) are they all for low pressure? That's why I suggested Teeing off the carcassing and checking flow upstream of each. Your shower valve is going to be an issue if its also for low pressure!

As I mentioned in my earlier post, check aerators/indices/filters for debris.

 

[Gasguru]

What's the flowrate at the hot and cold taps at the kitchen sink?

 

[polesapart]

More detail from the OP would be helpful here ; where exactly was the successful bucket test carried out? On the pipework feeding the bathroom or at the point of connection to a specific tap or mixer flexi? Hot, cold or both?

Some photos, of the bathroom and of the pipework from below, would help.

What make of brassware, and where sourced?