Dave Plowman (News) wrote:
In article ,
Graham Jones wrote:
I think that when it rains hard in a certain direction the flue on my
condenser boiler lets in rain water. This then runs through the boiler
and drips out from the bottom front corner. Does this sound possible?
It is definitely rain water as it never happens when it is not raining.

If this is happening you have a serious problem which should be
investigated immediately. The flue is connected (obviously) to the
combustion chamber and that combination should be totally sealed to the
room. It could be water is leaking round the outside of the flue and
finding its way into the room from there. But that too should be sealed.
Or, of course, the condensate drain if it's a condensing boiler.

Yes I've experienced similar myself, where I've had a leak at the bottom
of the boiler which I've traced back to condensate running back along
the (near-horizontal) flue and emerging from the outer sheath of the
flue, above the boiler due to a failed 0-ring there. No big safety
issue there. I imagine that incoming rain would/could follow the same
route.

Also, I've been whinged at by CORGISs about my boiler flue not being far
enough away from a facing wall (it's about 0.6 m away) - I've been told
that this is close enough for steam/condensate to be pushed back down
the flue. If that's plausible, then I'm sure incoming rain is too!

David