Air can't reduce flow at taps can it?

[WaterTight]

I'm thinking an airlock can only stop flow at taps.
Re-washered bath mixer tap the other day, gravity fed. Left job when hot started to come through.
They now tell me it's not coming out as fast as it did before. They say they had same problem last time they had work done and it was an airlock.
I'm thinking more likely blockage or something.
What would be your plan of action?
I'm thinking check tank to see if any debris has fallen in it, check ball-valve is working. Maybe try and send mains water down vent to blast out whatever is stuck.

 

[dontknowitall]

I'd get some new customers if I was you. The problems you've been getting recently are not normal!!!

Does the pressure and flow seem right for you? If not, perhaps a different washer will sort the problem? I used to fit large washers but now fit the smallest size possible as they allow more water to pass through. There's a "But" here. If it's an old tap then a standard 1/2" or 3/4" washer seems to work well. It's the more modern taps that seem to create problems.

 

[WaterTight]

Not been back to check yet. But he said it was like a "dribble." So perhaps it got worse since my work?
The tap looked fairly standard but the washers that fitted as replacements (or the very closest) were 3/8th ones. In bath taps. Unusual?

And I do seem to have my fair share of head-scratching events.

What do you reckon to my plan of investigation? After checking that I agree the flow is reduced and re-investigating the taps themselves...

 

[dontknowitall]

If it was me I'd try different washers ... then if it still doesn't work ... "New taps, Sir?"

 

[tamz]

An air lock can cause reduced flow.
Blow the mains back up it.
Learn to change washers without turning the water off. It is easy enough to do.

 

[Phil]

I've been through this, some plumbing systems can trap air in badly plumbed high spots, this will give a reduced flow.

I had it regular in one old house, the only outlet that could shift the airlock was the ensuite shower on full hot with the showerhead off.

 

[WaterTight]

Learn to change washers without turning the water off. It is easy enough to do.

In the abscence of isolation what do you do? Bung the feed?

 

[Phil]

Last time I opened all other hot outlets and the bathroom basin tap reduced to a tiny dribble.

Very easy to change washer then.

 

[tamz]

Open the tap then undo it.
Get a rag and place it on top of the hole and sit a pair of footprints on top to hold it there. (the water will run through the tap).
Change the washer and bung it back it.

2 minutes max.

You might like to wear rubber gloves if it is the hot depending on your pain threshold

 

[WaterTight]

I like that. I like that a lot. Thanks.

Hopefully sending mains pressure through the vent will remove air/blockage and I'll use that method in future.

 

[tamz]

Try it on your own taps first by just removing the head, cover it then putting it back in. Opening other taps takes some pressure away especially with mains. It is easy once you have done it a few times.

Never taught you that one in school eh

 

[Phil]

I have to say tamz, I only do this with the mains if the stoptaps seized or hidden etc!

Who was it on Screwfix forum who said he changed TAPS at full mains pressure? [insert a shocked face]

 

[easyt]

I have done hot water taps this way on a gravity system but never mains cold.

 

[HoodedClaw]

I hadn't thought of that Tamz, cheers, would have presumed the pressure would be to great - I'll give it a go next time, washes out the swarf when reseating too )

In the meantime Watertight, I'd stick my thumb over the end and back flow it with the cold as its a mixer? Had the same problem when I removed the cylinder for a base repair, flowed allright when I left, day later it had stopped. Backflowed through the kitchen mixer and it gurrgled and banged the air back tot he tank.

 

[kirkgas]

In the abscence of isolation what do you do? Bung the feed?

turn on all other taps fed from the same supply to reduce flow, have a cloth and screwdriver ready, remove trhe tap head and put the cloth over the hole in one swift movement, jam a screwdriver in to push the cloth down into the tap, change the washer as quick as you can keeping an eye on the cloth all the time as the pressure will try to push it out, when changed simply get ready to change over as quickly as you can, the trick is actually to stay calm, if you flap a bit you cant get the tap in and you spill water everywhere

 

[kirkgas]

I like that. I like that a lot. Thanks.

Hopefully sending mains pressure through the vent will remove air/blockage and I'll use that method in future.

pushing mains through the vent will work but means rigging something up to do it, why not try to push cold mains up from the kitchen taps, if single taps the best thing is the old style rubber mixer hose you used to get to turn bath taps into a shower hose (thats one for the oldies amongst us) i have one that must be about 10yrs old or more, i cut the hose connection to the shower, folded it and put some cable ties on to close it over, if the kitchen has a mixer tap, turn them both on and hold your hands over the outlet, not closing the outlet completely as neew taps dont mix the water till they leave the outlet, try to cup your hands over the outlet which forces the cold back up the hot, (while spraying water all over you unfortunately, but hey ho needs must) try to push it up for a minute or so then turn off the cold hopefully after a second or so of cold coming back down the hot you will get a gurgle of air followed by the hot, you sometimes need to do it a couple of times

 

[HoodedClaw]

neew taps dont mix the water till they leave the outlet, try to cup your hands over the outlet which forces the cold back up the hot

Use a hose connector with stubby bit of locked off hose - then your stay dry (but hold the hose connector on - they push off until your used to how tight that have to be on!)

 

[tamz]

I have to say tamz, I only do this with the mains if the stoptaps seized or hidden etc!

Who was it on Screwfix forum who said he changed TAPS at full mains pressure? [insert a shocked face]

That would have made a braw mess

 

[WaterTight]

I'm thinking an airlock can only stop flow at taps.
Re-washered bath mixer tap the other day, gravity fed. Left job when hot started to come through.
They now tell me it's not coming out as fast as it did before. They say they had same problem last time they had work done and it was an airlock.
I'm thinking more likely blockage or something.
What would be your plan of action?
I'm thinking check tank to see if any debris has fallen in it, check ball-valve is working. Maybe try and send mains water down vent to blast out whatever is stuck.

Ok...so went back. Poor pressure for hot and cold just at two his'n'hers style single-lever, quater-turn, mixer monoblocks on a twin basin set-up. Both separate monoblocks poor pressure. Cold not brilliant, hot like a trickle. I didn't work on these taps. I re-washered bath taps in same bathroom. Thing is...the cold on these is main pressure. So I disconnected the supply and ran a flexi off each into a bucket to check incoming pressure. Fine. Good pressure on both cold and hot.

So does anyone know why, after draining down and filling up, two separate monoblock mixer taps, which were never touched, might both develops faults dramatically reducing flow through them to a trickle with hot and heavy reduction on mains cold?

Please eliminate possibility that taps were already shot and customer is up to no-good. These people aren't like that.

Something to do with gunk? Or filters? Or the work of satan himself?

The problems you've been getting recently are not normal!!!

You said it!

 

[mikegas]

pushing mains through the vent will work but means rigging something up to do it, why not try to push cold mains up from the kitchen taps, if single taps the best thing is the old style rubber mixer hose you used to get to turn bath taps into a shower hose (thats one for the oldies amongst us) i have one that must be about 10yrs old or more, i cut the hose connection to the shower, folded it and put some cable ties on to close it over, if the kitchen has a mixer tap, turn them both on and hold your hands over the outlet, not closing the outlet completely as neew taps dont mix the water till they leave the outlet, try to cup your hands over the outlet which forces the cold back up the hot, (while spraying water all over you unfortunately, but hey ho needs must) try to push it up for a minute or so then turn off the cold hopefully after a second or so of cold coming back down the hot you will get a gurgle of air followed by the hot, you sometimes need to do it a couple of times

will washing machine hose off cold valve onto hot valve not cure the air lock or does this only cure locks when uve drained cylinder and have no water at all outlets?

 

[PlumbBobBob]

yes that should do the trick

 

[dontknowitall]

Mikegas - great tip thank you. Someone's probably mentioned it to me in the past but I'd forgotten that one.

 

[WaterTight]

Anyone? Help?

 

[tamz]

The taps are probably designed for high pressure (most single levers are) so the flow won't be great anyway. What size tails/flexis are on them?

You may?? have drawn a bit sh!e into it but not likely. Did you run them before you worked on the other taps? (remember that one when fancy taps are fitted to a gravity).

If the flow is clear from the pipes first check the aerator on the end of the tap for anything restricting. If that is ok strip the cassette out and check that. You may find some flux residue in there from years ago or a bit limescale. Give it a clean out anyway. If still not right it was probably like that.

 

[Plumbstar Tom]

Can you put another tap on the basin as a test? if that works then the issue is down to the tap and not a mysterious airlock

then if it is the tap I would strip it and try and flush it as best as possible