Condensate pipe blocked - finding the outlet

[Bateman1982]

Hi all,
my vaillant ecofit boiler stopped working this morning with error code f28. On closer inspection it appears to be related to condensate outlet likely being blocked.

If I change the outlet to run off into a plastic container the boiler runs fine, it's just when reconnected to the pipe that problems occur.

My problem is I don't know where to track down where this pipe actually emerges to see if the end is blocked.

It goes into the cavity wall then vertically down.
I can't see anything outside the house on this wall that could be it.
Only possibility is under the adjacent sink, there's a pipe that comes in from the cavity but I'm thinking that could just be from upstairs.

Pics attached:
1. Underneath boiler, white pipe is where condensate drains into

2. Underneath sink, can see white pipe coming in from cavity, could this be where it's draining?

 

[Wayners]

When you say cavity I assume you mean behind the dot and dab plasterboard walls.

You don't mean in the brick cavity.

Looks like you have found it connected in your last picture.

 

[Bateman1982]

Oh yes, sorry my terminology isnt the best as I don't have much experience with this.

It does seem like I've found it.
Disconnected it under the sink removed a tiny bit of gunk from the pipe (really not much), reconnected it and so far so good.
Be surprised if it was just that causing the issue but so far so good after running the boiler for 10mins

Cleaned the condensate trap as well just in case.

 

[gas112]

yep thats certainly looks like the connection under the sink very common connection undo it it will be full of gunk from the sink

 

[endecotp]

Use a wet-and-dry vacuum to suck the remaining gunk out of the pipe. (Disconnect from boiler; suck from sink end.)