Sink won't drain but there's no blockage?
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Thanks for the offer Nigel. But can you think of anything that might cause this phenomenon?
Yes, third post in this thread...Ok so i had a little pun@ slugbaby....but slug,lump, clod. same thingtrickiedickiedido said:
. IT`s so simple . the sink pipe goes to a bigger vertical pipe(block of flats) I`ts blocked somewhere. I rest my case M`Lud.
I refer to my earlier post.
I am no means an expert but if there is no blockage and correct fall is there, the water HAS to drain away.
Maybe a vaccum is being created and you need to let some air in to allow drainage.
Wheres Chris R when you need him?
I am no means an expert but if there is no blockage and correct fall is there, the water HAS to drain away.
Maybe a vaccum is being created and you need to let some air in to allow drainage.
Wheres Chris R when you need him?
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Nobody answered Bahco's question from way back, and looking at the photo, I think he has a good point. It looks to me as if the horizontal pipe disappearing behind the back panel of the sink unit does in fact run uphill.Bahco said:
This could offer an explanation for the problem. The uphill section traps water, so there are then two traps with a body of air trapped between them. When water is poured into the top (proper) trap, the air between is pressurised and so resists the flow of water, which is reduced to a trickle.
Creating an opening into the section of trapped air will allow it to depressurise and then it will be carried away with the flow of water. This fits with what the poster is telling us. The answer would then be to shorten the vertical section of pipe before the uphill section so making it fall correctly.
It is also possible that there are other uphill sections of pipework further on, which might compound the problem. Anyway let's hear what happens if you do what I'm suggesting (and what Bahco touched on in the first place).
Cheers Chris.
Thanks chris. I think the answer must be along these lines.
The horizontal pipe isn't exactly as uphill as the photo suggests (just the camera angle) but there does seem to be some kind of trapped air issue. Whne the sink has sitting water in it, and I slightly unscrew one of the joints, there is a seeping of air and the water gurgles away quite happily.
I will see if there is any way of improving the fall on the pipes.
The horizontal pipe isn't exactly as uphill as the photo suggests (just the camera angle) but there does seem to be some kind of trapped air issue. Whne the sink has sitting water in it, and I slightly unscrew one of the joints, there is a seeping of air and the water gurgles away quite happily.
I will see if there is any way of improving the fall on the pipes.
I'm wondering if the vacuum is being created by water syphoning into the washing machine. Could you loop that WM pipe over the back rail and re-connect it?
My Biggest hunch on this is that you may have a resriction further down the pipe and probably where it joins into the stack.
A sagging pipe full of water and crud would have the same effect
I suspect that this restriction will let water by at a low rate which I would expect you to be able to get through your pipe under the sink but when you let a sink full of water go it backs up.
Another idea I have, fresh from the twilight zone, is that some floatey material eg fat or polystyrene has created some sort of valve somewhere. Pretty rare but you will be amazed at some of the things we see.
It sounds as though an anti syphon device might be of some assistance but only as a last resort when all other straws have been grasped. Item number CW20 on page 4 HERE
My Biggest hunch on this is that you may have a resriction further down the pipe and probably where it joins into the stack.
A sagging pipe full of water and crud would have the same effect
I suspect that this restriction will let water by at a low rate which I would expect you to be able to get through your pipe under the sink but when you let a sink full of water go it backs up.
Another idea I have, fresh from the twilight zone, is that some floatey material eg fat or polystyrene has created some sort of valve somewhere. Pretty rare but you will be amazed at some of the things we see.
It sounds as though an anti syphon device might be of some assistance but only as a last resort when all other straws have been grasped. Item number CW20 on page 4 HERE
Slugbabydotcom said:Another idea I have, fresh from the twilight zone, is that some floatey material eg fat or polystyrene has created some sort of valve somewhere. Pretty rare but you will be amazed at some of the things we see. 3rd post on this thread........always knew I was in a strange zone
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I suppose Joe had better have go as this thread is getting silly.
The fall of the pipe isn't suddenly going to change. It used to work then suddenly stopped.
He's taken the pipe to bits and it's all clear.
When it's fully assembled there is pressure when he tries to clear it with a big sucker.
The fault is obvious. There is a blockage further down he pipe.
When he releases the sink it backs up.
When he tests the pipe the water flows - AND THAT IS BECAUSE HE DOESN'T TIP ENOUGH DOWN TO SEE IT BACK UP!
Tip a load of caustic soda down at night and it will be clear in the morning.
If you think the seals are damaged by it - replace the fittings.
joe
The fall of the pipe isn't suddenly going to change. It used to work then suddenly stopped.
He's taken the pipe to bits and it's all clear.
When it's fully assembled there is pressure when he tries to clear it with a big sucker.
The fault is obvious. There is a blockage further down he pipe.
When he releases the sink it backs up.
When he tests the pipe the water flows - AND THAT IS BECAUSE HE DOESN'T TIP ENOUGH DOWN TO SEE IT BACK UP!
Tip a load of caustic soda down at night and it will be clear in the morning.
If you think the seals are damaged by it - replace the fittings.
joe
trickiedickiedido said:
I only charge £30 to point out the obvious
Boil up a cauldron of water - a gallon is ok, preferably two. Plus a kettleful.
Hook up that WM pipe as previously advised.
Tip all the boiling water down together. Low tech but cheap and it might work. I've tested washing machine sludge and big lumps of fat I've retrieved from drains with sodium hydroxide, hydrochloric acid, and sulphuric acid. Separately, that is. None of them is a patch on boiling water. I bet it's different, at least, afterwards.
Sodium hydroxide can be OK overnight on some blockages. Sulphuric acid is amazingly good on many things, like old sh1t, and towels. But do NOT use them together!
DO NOT use bleach either.
Any of the above, except the boiling water, can wreck your nice sink. You have been warned!
Hook up that WM pipe as previously advised.
Tip all the boiling water down together. Low tech but cheap and it might work. I've tested washing machine sludge and big lumps of fat I've retrieved from drains with sodium hydroxide, hydrochloric acid, and sulphuric acid. Separately, that is. None of them is a patch on boiling water. I bet it's different, at least, afterwards.
Sodium hydroxide can be OK overnight on some blockages. Sulphuric acid is amazingly good on many things, like old sh1t, and towels.
But do NOT use them together! DO NOT use bleach either. Any of the above, except the boiling water, can wreck your nice sink. You have been warned!joe-90 said:
I really do wish it was that simple. OK I'm no expert but there is something not right about this being a blockage.
I have poured a 2ltr bottle of water straight down the back, vertical pipe and it has flowed away fine. When all the pipes are assembled and I turn on the tap, it takes about 5 seconds for a gentle trickle of water to cause the water to back up (in other words, a lot less than a 2ltr bottle of water).
I realise a blockage is the obvious answer but it really doesn't seem like the situation here. maybe the HepVO suggested above is the solution.
On further investigation the pipe carrying the water out of the flat does seem to extend some way horizontally (hidden behind skirting board) and who knows what has happened there. I'm glad someone else has posted a similar problem so at least I know I'm not going mad here, but I have had enough. I've asked the landlord to send a plumber round and they can sort it out between themselves, blockage or no blockage!
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