Any combis that can use a lined chimney as a flue?

In news:dr2khc$omh$ snipped-for-privacy@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com, Dave scribed:

Combis have sealed (to room) combustion chambers, so need to *ingest* clean, oxygenated air as well as *expell* burned, de-oxygenated gases through the same flue. As a result, the flues are double walled, creating separate conduits for clean and burned air. Do you see where this is leading? ;-)

hth Nigel

|In news:dr2khc$omh$ snipped-for-privacy@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com, |Dave scribed: |> I asked something similar a couple of weeks ago and have followed-up = on |> various sites but so far drawn a blank. |> Does anyone know of a Combi that could be fitted in a ground floor |> cupboard next to a 2 storey chimney breast with the flue going up the |> chimney breast? There is currently a Baxi back boiler fitted. |> How would the flue liner be installed? there's no access to the first |> floor flat. |>

|> Dave | |Combis have sealed (to room) combustion chambers, so need to *ingest* = clean,=20 |oxygenated air as well as *expell* burned, de-oxygenated gases through = the=20 |same flue. As a result, the flues are double walled, creating separate=20 |conduits for clean and burned air. Do you see where this is leading? ;-)

A long double walled flue up the existing chimney. Combis normally have lots of different flue fittings. So does the = proposed combi have the appropriate fittings and does it allow a sufficiently long vertical flue. *read the manual* which may be on line.

--=20 Dave Fawthrop

Thanks, but I was aware of that. I assume that some combis are spec'd to work with a long balanced flue but I haven't been able to find one by poking around on the web. I was hoping that someone on here might be able to point me at a suitable boiler and explain HTH I might get the flue into the chimney.

Dave

Keston now do a combi that needs 2 x 50mm muPVC pipes for air inlet and flue. According to the instructions you can run them up a disused chimney but how easy that would be to do in practice is another matter.

just to make the installation possible.

BTW how are you going to deal with the condensate?

In news:dr2vhg$if8$ snipped-for-privacy@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com, Dave scribed:

My apologies, Dave. I read your OP to mean that you wondered if you could just use the chimney as a surrogate flue. ;-)

Best of luck Nigel

The plan for the condensate was to pump it. The cupboard currently contains a DHW cylinder and a header tank for the primary circuit so I was going to use the existing overflow pipe from the header tank - mmm, but this just vents into the garden and the only drain that's available goes to a soakaway - maybe not a good idea after all.

Possibly back to plan A: keep the back boiler and vented primary and fit a small thermal store or pressurised DHW cylinder.

Dave