Locating boiler condensate discharge

[Martin Pentreath]

Hi all,

Just engaging in what management-speak calls succession planning ;-)

Our current non-condensing combi boiler is on an external wall, ground floor, in a cupboard, not near any drains either internal or external. When it goes to meet its maker (Ariston in this case) we'll be needing a condensing model. I'm not clued up about what happens to the condensate discharge. Looks like it's normally a bit of plastic tube that's intended to go to an internal drain or tundish. Can it go into a tundish in the boiler cupboard which discharges onto the paving outside? It would be going out to a seldom used bit of our garden. How much water do these things put out anyway?

Cheers!

Martin

[William McNicol]

Quite a bit... My boiler is in the cellar and the condensate goes to a (loft type) water tank which has a pump with a float activated switch. I haven't measured how much I collect, but there's probably enough to have a bath in it every two or three months or so...

You probably wouldn't want to be discharging on to the paving (although it would probably keep it very clean) since it is a bit acidic (said to be similar to vinegar iirc) and is probably against one of John Prescott's laws.

Saniflo produce a special designed system for pumping away condensate when there is no suitable drain nearby.

Cheers,

William.

[David Hansen]

On Wed, 13 Aug 2008 05:15:40 -0700 (PDT) someone who may be Martin Pentreath wrote this:-

Slip hazard in winter, so not a good idea.

However, it can go to a small soakaway.

[John Stumbles]

which should be filled with limestone chippings (or the contents of an old well scaled up HW cylinder) to neutralise it.

[Andy Dingley]

Enough to be visible, too much to catch in a bucket (you'll forget to empty it), but not enough that you'll think inflicting a Saniflo on yourself is worth it.

It's also slightly acidic. Enough to make a mess of mortar or paving slabs. Barely enough to be interesting to watch if you let it trickle over a limestone rock. It's certainly enough to dissolve a tiny amount of copper from pipework and then deposit this as a bright green stain down an outside wall, should you install it sloppily.

[David Hansen]

On Wed, 13 Aug 2008 14:40:36 GMT someone who may be John Stumbles wrote this:-

Possibly better to find some acid loving plants, which would presumably welcome the condensate dripping on them.

[DavidM]

I've potentally got a similar problem with a new boiler I'm planning on having fitted in a 1st floor airing cupboard. At the moment the plan is to drop the condensate pipe through the kitchen ceiling, along the wall at high level (boxed in) then out through the house wall, then along the wall to pick up a drain pipe somewhere. All a bit messy.

A possible option might be just to drop the pipe down through the floor of the airing cupboard, down inside the opened up chimney breast below (just a cupboard), down through the floor boards and then discharge into the underfloor void, which is about 4ft below the floorboards, and is just earth and old building rubble. The underfloor space is quite well ventilated.

Is this idea even a starter?

David.

[Dave Plowman (News)]

Surely it's one of the few things where plastic is de rigueur?

[John Stumbles]

No! It's the sort of arrangement that gets the term "DIY" used in a perjorative sense. Just do it properly and don't worry about the constant build-up of damp under your house in the winter months when the boiler's working hardest.

[Andrew Gabriel]

When I first fired mine up, I ran it into a bucket, mainly to see how much it produced. IIRC, it was not far off a bucket-full from leaving it running all night.

Remember that long outside runs are liable to freeze. Mine said to use 32mm pipe minimum for outside runs.

Probably really good if you want to cultivate dry rot down there ;-) That's what happens with long-term leaks in heating systems.

[The Medway Handyman]

Thats what my CORGI bloke told me to fit as well.

[Rod]

If using a soakaway you are supposed to get permission from the Environment Agency.

I got in touch with them, a very helpful person asked for my exact location and said "fine". I had to ask for a letter to prove it - should that ever be needed. But I did get the impression that they might have refused in another location.

[Ed Sirett]

The Sanicondens unit is /much/ smaller tan one of those dire WC stick bomb attachments. They are reliable (installed about 1/2 dozen with no problems so far).

[Pete Verdon]

[...]

Hmm, interesting. Mine is currently (not done by me) just bunged through the wall and left to drip into the narrow gap between house wall and garden wall. I don't know whether the ground there is soak-away-into-able, or concrete as it is further down the gap. Am I likely to be slowly dissolving my house?

Pete

[Andy Dingley]

I wouldn't argue with that.

Seen plenty "professionally" plumbed in copper though. Friend of mine has just bought a house, her upstairs boiler is very neatly plumbed this way. It even has the copper turned back on itself outside, so as to guard against draughts and to make sure that the condensate goes straight down the render.

[Andy Dingley]

How do you make a reliable Saniflo?

Pump weak acid through it....

I rest my case.

[Andrew Gabriel]

Are you sure that's not the pressure relief outlet?

Mine you I've seen loads of recently installed combis with copper pipe routed around the outside of the house, and not one is sleaved where it goes through the wall.

[DavidM]

OK, will abandon this idea. I guess my plumber would have firmly stomped on the idea anyway, so at least I don't feel a twit in suggesting it to him.

Is it allowable/sensible to run the condensate pipe under the first floor floorboards to a point where it can go through the wall into an existing hopper that carries rain water, and water from basin and shower down to a gully at ground level. What fall is needed on the horizontal sections of pipe, and what's the minimum size pipe that can be used (the pipe would need to go through floor joists for about 1 metre)?

I'm just trying to think outside the box to see if there is a less unattractive way of routing the pipe (the boiler will be in the centre of the house, with no convenient access to an outside wall - the flue is going up through the loft and out of the roof - plumber is ok with this).

Thanks for the feedback.

David

[John Stumbles]

The problem with "Saniflos" (WC macerator + pumps) is not the pump. After N[1] thousand years pumps are fairly much sorted technology; unfortunately attempting to chop up into little bits and pump away anything that humans may chuck down the WC pan (out of sight, out of mind[2]) is a little more tricky.

[1] where N is at least 2: think Archimedes' screw [2] supposedly translated from English -> another language and back by a computer translation program as "invisible idiot".

[YAPH]

If the pipe is coupled directly to the boiler you may find the mfr calls for a minimum 45 degree fall(!). What I sometimes do is have a foot or two of 21.5mm vertically down out of the boiler into an open topped bit of

32mm (like a washing machine waste stand pipe) and run the 32mm (which can go down to 21.5/22mm again if needs be going through joists etc) along horizontally, then up a few inches to make the whole horizontal section act like a trap) and then into a drain.

-------- | | | boiler | | | soil -||----- stack || 21.5 |||| | | | | 32 | | | | | | | | ------ | | | 32 or 21.5/22 | ---- | | ------------------------------- | | | ------------------------------------- | |

Or just spend the £100 or less and get a pump.