Boiler gurgling after water goes down sink.

[jango]

Vokera unica HE boiler.
I got a new kitchen fitted a while ago and the fitters routed the condensate pipe wrong so it flowed uphill.
This made the boiler cut out a lot.
The condensate pipe has now been re-routed and it doesn't cut out anymore, but every time water goes down the sink, the boiler has loads of air bubbling up inside it.
The bubbling only happens after the last of the water has went down the sink.
So if I have water constantly running down the sink, it won't bubble up, it's only once the water goes away.
It also bubbles up after I have switched the central heating off.

I'm happy that it doesn't cut out any more, but is this bubbling something that needs fixed? Should it be doing that?

 

[newcastle phill]

Can you add images of the cndensate run including clear images under the sink

 

[jango]

This is where the condensate pipe meets the sink.

 

[newcastle phill]

I take it those condensate/washer hoses coming in from the side ?

If so - im not surprised its gurgling as there will always be a residual amount of water in the pipes that will interrupt the condensate.

What i can say is i was at one a while ago that was plumbed in just like that and the boiler trap was gurgling when heating was on and sink emptied it created backpressure up the condensate into the boiler trap.

I would not have plumbed it in like that side on. Over time when bits of food and fat go down the drain it will clog and congeal wherever.

 

[jango]

Yes the condensate pipe is the lowest pipe at the back coming in from the left.
The guy who fitted the new condensate pipe connector said it was a type that won't allow water to flow into the condensate pipe from the sink.
But, as you said, the problem here is air flow.

 

[oz-plumber]

The condensate pipe is plumbed into the main drain - untrapped.
I would assume from the photo, that the condensate trap in the boiler is operating as a vent for the sewer system.
It may even produce sewer smells coming out of the boiler.

I would have it re-plumbed so the condensate connection is upstream of the trap.

Should stop all the gurgling

 

[newcastle phill]

I'd be surprised if there is any sort of valve in that. And even if there is - ideally there shouldnt be as it willl create a double trap.

If you remove the screwed joint closest to the condensate and look/feel inside.
Use a bowl under - there may be a little water in...

The sink is pulling the boiler trap

 

[king of pipes]

Get it rerouted to the drain out side up size it to 32 mm that will solve your problem

 

[jango]

Thanks for the help guys.
I've attached a better image showing all of the pipes.

oz-plumber. When you say upstream of the trap, do you mean have it connected to the same place as the washing machine outlet (the grey coiled pipe)?

king of pipes. Do you mean get it routed outside the building so it goes nowhere near the sink?

 

[jango]

sorry for the extra post, it looked like my last post didn't work so I posted it twice.