Help cure a gurgling handbasin?

[qprfact]

We've been in our house just coming up to a year, and really now want to get the gurgling noise in the sink in our en suite sorted!

Basically it keeps gurgling for some time after water has drained - quite loudly!

I think it's because we have quite a long piece of pipe that takes the waste out, and the pipe is pretty much horizontal for most of its length.

I bought an anti vac trap thinking I could try it myself, but before I got to taking sink off the wall I took pics off the current setup and to my untrained eye that looks like what I have just bought!

Is there something else I should try?

Plumbers in the Southend area who fancy doing this for me would be warmly welcomed!

 

[Kyle87]

Increase the thickness of the pipe maybe. It gurgles because it's creating a vacuum as the water passes down...... Unless I'm mistaken.

 

[SilentMike]

hard to see from the picture the anti vac valve is normally on top of the outlet just before the thread
dosen't look like it is tbh

 

[Dave]

Gurgling sink. Lol.

Tell her to spit it out :lol:

 

[jtsplumbing]

What you have is a Bottle trap ! looks the same but anti-vac trap will have a small air inlet valve on top ! did you ask for an anti-vac trap ? other type to use would be a Hep2o Trap.

 

[Howsie]

I'll be in Leigh on Sea at the weekend if that helps?

 

[mountainman]

A visit to the cockle sheds then!

 

[Bernie2]

Hmm! Sometime they perhaps sell traps as anti vac when they are really resealing traps. The difference is that usually an anti vac trap has a small air vent on it to break the vacuum and a resealing trap retains some water in it until the vacuum has stopped then the water falls back into the seal to reseal it. But that is some weird set up you have there. I would imagine it blocks very quickly and not a rodding eye in sight. To say it breaks the recognised standards is to put it mildly. Have a look at Building Regs Guide Doc H Drainage to get some idea of what I mean just Google it, its a free UK gov download.

 

[ManchesterGas]

Oh dear, that pipework looks a bit naff there. For the trap problem I'd fit an anti vac trap, no more gurgling then!

 

[lexicon101]

Another thing possibly (unless my memory is incorrect), is that it could well be an anti syphon bottle trap you already have, however sometimes, assuming it is a mcalpine fitting , it may well still have one of there blue stoppers inserted , which on occasion I have seen inside the air admittance section of the trap, it basically is a cap, that screws off, and you can remove the plug, much like mcalpines sink traps with washing machine waste connections, if that makes sense...

 

[Guest123]

Where the waste pipe terminates through the floor with a bend, change this for a tee and 11/2" air admittance valve and this should solve your problem. Use one of the triple A rated ones by Floplast and it can be fitted below the flood level of the highest appliance.

 

[Koogatubac]

Either install a HEPvO trap on the horizontal run
Or
Change the bottle trap for a anti vac S/P Trap

I dont really like to put bottle traps on basins, only put them on urinals

 

[qprfact]

Thanks all for your replies! I didn't realise the pipework under the basin wasn't good (wouldn't know what to look out for!). What I have bought is definitely a Floplast Anti Vac trap, so it looks like this could replace the bottle trap I already have. Although system3's suggestion about adding a tee where waste pipe goes down sounds a lot less invasive!

@Howsie - could you maybe send me a PM if you are nearby this weekend?

Thanks again everyone

 

[Bernie2]

I doubt putting an anti vac at the point were the pipe goes under the floor will do much good other than vent the leg from the bend into what i assume is a soil stack somewhere. Unless you fit some anti vac device from the bend going under the floor at the end of the pipe at the basin it will still probably gurgle. What is probably happening, is that when the basin water is released it surges down the flat pipe filling it and making for a vacuum behind it. Waste pipes are supposedly intended to only flow partly full allowing trapped air to escape over the top of the flowing water. In a flat pipe full from wall to wall with water it forms a plug of water which acts like a plug and in front of the plug it pushes air and behind the plug it pulls air making a vacuum. The design of waste pipe systems should be to avoid this happening, it is what is known as hydraulic leap or jump a well recognised problem. Think of it as a bicycle pump, the plunger washer in the pump pushes air out and behind the washer it pulls.

 

[stevetheplumber]

the real answer is to get some fall on the pipeworkits probably gurgling because its partialy blocked when you take the trap of lift the pipe work see if it feels heavy
even lifting the end nearest the basin by 30mm would help