Plumbing query - Combi run off water

[dig dug dan]

Did a patio with a mate, and the guy who installed the new boiler left the water run off pipe sticking out the wall, discharging on the ground. Before we laid the new paving, they got another plumber out to sort this as the pipe is supposed to discharge into a soakaway.
We dug a hole for him, and he turned up with grey plastic pot, with the limestone chippings inside and plumbed this into the boiler run off pipe.
He said we could now pave over it.
Now the boiler keeps stopping, and the water is backing up the pipe.
A different plumber has stated that the limestone clippings should go on the outside of the chamber, and it should be empty, and also it should have a manhole cover as the limestone should be replaced every 6 months.
The customer is fuming, not with with US as we did everything to instruction, but with the plumber who installed.
Can anyone shed light on this.?

[enigmaenigma]

Disclaimer: not a plumber

That said, and what you describe, seems like a condensing boiler

Combination boilers have a blow off on the external wall, but these are for pressure relief…hence they are bent in towards the wall, to avoid a pressure relief of scalding water in the face

As for condensing boilers and the corrosive steam vapour / water that’s constantly created

Whilst they need to be discharged properly, due to the corrosive, they are prone to freezing and stopping the boiler working…so I wouldn’t want it buried / inaccessible

[lutonlagerlout]

IME dan the pipe that comes out of the boiler has to run to a back inlet gully
looks ugly 22mm white pipe running down the wall but its a requirement
the flats we are doing right now both combis have this pipe running into 2 BIG s that i installed for this very purpose.

I take it the plumber commissioned the boiler and signed it off,if so its a matter for him to resolve
LLL

[dig dug dan]

Exactly tony. Not our problem although I might be lifting the paving to get at the soakaway!

[rimexboy]

My discharge from my boiler runs to my waste under my sink , past the u bend. As you say if they run outside and are not insulated they will freeze up and shut the boiler down

[bbbbristol]

A bit of info here - page 20
http://www.idealheating.com/downloads/manuals/206743_inst.pdf
Best to insulate the pipe if its outside,

[dig dug dan]

We did indeed insulate the pipes externally!

[Mikey_C]

did the soakaway look like this?

[dig dug dan]

Yes.that's exactly the one

[Mikey_C]

the condensate is acidic (supposedly about the same as vinegar) with regards limestone and 6 month replacement I presume the "lime"stone would counter (spelling?) act the acid? my boiler produces about an egg cup per hour of operation. and goes straight own the drain.

[Mikey_C]

like any soakaway the ground has got to soak up and away the water. i.e. i am guessing the won't work in clay.

[dig dug dan]

Well it is clay, and I think here lies the problem.
Customer may have to run it to a foul drain

[local patios and driveway]

IME dan the pipe that comes out of the boiler has to run to a back inlet gully
looks ugly 22mm white pipe running down the wall but its a requirement
the flats we are doing right now both combis have this pipe running into 2 BIG s that i installed for this very purpose.

I take it the plumber commissioned the boiler and signed it off,if so its a matter for him to resolve
LLL

Spot on. Should be 22mm insulated pipe, if a condenser pipe freezes you can get all kinds of issues in the winter.

[Tony McC]

Here's the installation guidelines PDF Format

Basically, it's a placky boss connector with a lid, half a dozen or so extra holes, and a tenner on the price. I can only assume they recommend the use of limestone chips as a counter to the acidity of the condensate, as normally, we recommend limestone chips NOT be used for soakaways and lan drains beause the disolve and precipitate over time due to the natural acidity of rainwater.

[lutonlagerlout]

"should only be used in porous soils"
fail
tbh it looks like an ideal gizmo for attaching to the end of linear channels adjacent to footpaths
It falls within the remit of the SUDS legislation
when they talk of not practical to run into drains ,what they mean is too idle to install a new drain in most cases
LLL :;):