Condensate drain

23 Oct 2016
Reaction score
United Kingdom
Hi, I have an existing combi installation with the condensate drain going out the front of the property through garage wall which then goes underground and into a drain about 1.5mtrs away.
I want to put in a new block pave drive and have no need for the drain to be there - is it possible to cap it off permanently (leaving the cond drain pipe connected) and bury beneath the block work, or should I leave access to it?

I’ve also considered running the drain pipe out of the rear of the garage and into a McAlpine type soakaway device, but the pipe run will just exceed the 3m limit, and I’d need to bury the device below ground along with the drain pipe - is that permissible?

Many thanks for any answers or advice.
Sponsored Links
By "cap it off", I assume you mean just cover the drain, but leave it functioning.

I, personally, would leave some access to it, so that if it ever gets blocked up, it can easily be remedied. You may, however, have a manhole close by to achieve this. Perhaps consider a nice gulley with paving around it?
Is it a gulley at the moment?
The 110mm parts can be left underground but you need access to clear blockages. Presumably it's only condensate going down so unlikely to block but personally as above I'd leave a cover, even a back inlet gulley or similar.
You'll need to make sure there's still a water trap somewhere. If the boiler has one built in there's likely an air break after, so you would still need another one
Photos would help.
Thanks guys for your replies. I was wondering if there is a way of connecting the condensate drain pipe to the 110mm pipework and sealing it off then paving over all of it so no need for a cover at all. I guess that also means no access if the drain blocks and backs up?

My other option is the mcalpine soakaway cylinder with limestone chippings - can that be positioned below the ground, including the 500mm or so condensate entry pipe? if so, I can conceal it all, I'm just concerned about the pipe run from boiler being a little over 3M?

Many thanks
Sponsored Links
You can solvent weld a boss to 110mm plastic or put an adapter on the end down to 50/40/32mm pipe then you can adapt that further to 21 over flow pipe. That's no problem.
If you can clear the drain from upstream then that would be fine. Just imagining if the main drain blocked and Back flowed a bit and you needed to flush out the pipes. As long as you're happy with the access then go for it.
Ps the pipe run can be whatever you like, just make sure there's an air break somewhere and then run the rest in 32mm solvent weld.
John, many thanks for that advice, especially re the pipe run length. I think I might go for a soakaway at the rear to avoid any issues with the drain blocking etc.

Thanks again
No I don’t think it’s a job for an RGI, it’s about making sure the condensate can drain properly and in line with guidelines from BS.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links