Very slow draining basin - please help

[matthew4444]

Hello All

As the title says my bathroom basin is taking an age to drain. It's been in about a year and for 9 months worked fine however the last 3 it's started to drain slower and slower and slower. A blockage I hear you say. Well I've chucked various cleaning products down it with little effect.

I've removed the trap (a Marley Monitor anti syphon bottle trap) and given it a good clean and cleaned the waste pipe with the trap off by squirting hot water down it. It drains away fine and all appears okay. After reassembling the problem remains. The water is backing up fairly quickly suggesting a fault with the trap but I'm flummoxed and can't see what the problem is with it. Whilst cleaning the trap the water runs through it without problems it's just when it is attached to the basin. Does anyone have any suggestions?

Kind regards

Matthew

 

[Bahco]

Is there a fall on the basin waste pipe and does it drain into a soil pipe?

Does sound like your soil pipe ha a blockage though.

 

[matthew4444]

Thanks for the quick reply.

The basin waste drops vertically (about 0.8m) and then runs under the floor and outside into the soil sack. The overall length of the pipe is about 5m in total with a steady fall. I've had a look in the inspection chamber for the stack and all appears to be flowing normally ie. for the WC waste.

As I mentioned it backs up fairly quickly in the basin but when I removed the trap and squirted water into the waste pipe it flowed away ie. it didn't back up which is why I thought the problem may be with the trap.

 

[Bahco]

If it was me I would renew ALL the waste pipe to the point where it reaches the stack.

Cost you less than $10 and you will discount that part as being the cause if the problem persists.

 

[clf-gas]

Anti syphon not allowing air in, replace with bog standard and your woe's will disappear, untill the toothpaste starts blocking it in a few years

 

[matthew4444]

Many thanks for the replies.

Bahco - Replacing the pipework is not really practical. The tiled floor has only been down a year - would be a bit of a nightmare to do.

Clf-gas - how does the anti syphon work and why is it not letting air in? Reading some of the posts on here the recommendation generally seems to be for anti syphon traps.

 

[clf-gas]

Many thanks for the replies.

Bahco - Replacing the pipework is not really practical. The tiled floor has only been down a year - would be a bit of a nightmare to do.

Clf-gas - how does the anti syphon work and why is it not letting air in? Reading some of the posts on here the recommendation generally seems to be for anti syphon traps.

Anti syhon traps have a small valve above the trap that allows it to draw in air, this is done via a small rubber diaphraghm.

Go to one of the big outlet sheds in the morning buy a standard trap, P or bottle and try it, think you'll find your woe's are no more.

 

[dal5band]

Can you disconnect the trap from the waste pipe and run it into a bucket and test it that way. You will probably need to get the pedestal out of the way.

 

[matthew4444]

This trap doesn't seem to have an external valve - please see the link below. So I'm not sure how it's supposed to work.

http://www.marleyplumbinganddrainage.com/specifier/catalogue/1515/1679/traps.html

dal5band - it's in a vanity unit so running it into a bucket wouldn't be easy.

They don't make things easy do they!!

 

[matthew4444]

To update on this one. I purchased a standard McAlpine bottle trap, connected it to the basin and lo and behold the waste pipe wil not grip in the trap. It has the usual plastic nut, plastic washer and rubber seal but the compression fitting will not hold the waste pipe. Both traps say 32mm / 1.25" yet one grips the waste and one doesn't!!

I sent an e-mail to the technical dept at Marley asking about their trap pipe sizes and the person who replied didn't really answer my question and went on about push fit and solvent weld pipes and that Marley traps have tighter fitting. I'm now totally confused as I have two traps one fits to my waste pipe and the other doesn't yet both are supposed to be the same size.

Am I doing something fundamentally wrong? Can anyone help?

 

[dal5band]

Just double check the bits are all in the right order and the right way round.
Onto the pipe goes the nut, then a thin flat washer, then the rubber seal with the bevelled side outer most. You can't just push the pipe into the fitting.
With the nut drawn back, you should be able to see that the pipe goes into the fitting with the rubber seal making a close fit.

 

[matthew4444]

Thanks for the reply. Yes, the bits are all present and correct. The plastic nut from the Marley trap will not screw onto the McAlpine trap and vice versa. It's only by fractions but it won't go. The McAlpine one is just slightly bigger. As we put in Marley waste pipes and traps I'm sure it's a ruse by Marley to ensure that only their traps can be used with their pipes!!

 

[dapper100]

Nice to see i am not the only one, I had a sink trap, had no idea what type but when i purchased what should have been the correct pipe,....the pipe and trap and bends wouldnt fit together, like you say a minimal difference but it wouldn't grip.
The problem was the pipe i brought just didnt match.


To save me running around and wasting money, I replaced the whole run from scratch.

 

[cider]

Dont understand how a faulty antisyphon trap can cause your sink to not run away! these have an air admitance valve fiited to prevent vacumn in the pipe from pulling the water seal and thus stopping gurgle noises and smells. The problem is probably the pipe sagging under the floor which has now filled with nasty things

 

[matthew4444]

Thanks for the replies.

The quote from the man at Marley regarding their trap was:

"our Marley monitor anti-syphon bottle trap do not have a rubber type sniff valve, it works on a different principle, in that there is a air way between the inlet and outlet tube inside the trap that breaks the syphonic action during discharge."

Do you think it could it be this part of the trap that is not working properly?