How to stop drains gurgling

[Steve]

I may have pooped up my drainage plumbing. When my bathroom was fitted 3 years ago the basin and bath drains went out into a downpipe with a gulley at the top. I altered this so they now join together outside and go into the soil stack via a strap on. This was done because the drain this went into was blocked up and has now been removed.

Additionally, the boiler condensate joins to the bath waste under the bath. The 22mm goes straight from the boiler and changes to 40mm under the bath.

Now, when the bath is draining, both the basin and the boiler can be heard gurgling. Is this bad, and is there a way to stop it? And is this why american houses have vents at every appliance?

In the picture, the far right pipe is for the bath. It goes in about 3ft, branches up to bath, then changes to 22mm, goes further in about 6-7ft then up to the boiler.

The middle pipe is 32mm to the basin, about 6ft straight run under the floor then up to the basin.


Worth noting the horizontal white pipe had much less fall on it when i fitted it. I had the bottom of the soil stack replaced and when they did this the stack moved down about 6 inches. Is this the problem?

 

[Newboy]

when the bath is draining, both the basin and the boiler can be heard gurgling

That's the sound of water being pulled out of the traps.

You can cure that basin gurgling (probably) by fitting an anti-vac / AAV trap.

The boiler trap being pulled is a slightly more serious matter - an empty trap could let flue gases into the room - worth having an RGI have a look at fitting an additional trap - technically the condensate drain is classed as part of the flue arrangement so needs to be checked by a GasSafe registered engineer.

PS - That is one of the worst waste pipework installations I've seen recently (no offence intended)

 

[Steve]

PS - That is one of the worst waste pipework installations I've seen recently (no offence intended)

Thanks. It was a rush job tbh. I had discovered the gulley below was leaking waste water into the water meter chamber adjacent and was also blocked up so decided to go that day and get the pipework to divert it. Unfortunately b&q only stock white solvent weld. The horizontal was a little more level when I fitted it as I said above. The stack has dropped when the ground work was done.