Peter Hawkins wrote:
My house is Oil Fired CH but the living room also has an open grate.
The problem is that in the winter there is a huge draught up the
chimney when the wind blows. This draught is so strong that it has
bowed the living room door from the air being drawn from the hall. It
is also strong enough to allow me to burn fuels like Phurnacite,
typically used in glass fronted fires.

Obviously this makes the room very hard to heat with a radiator. Is
there any sort of baffle or cowl which can be installed on the chimney
to limit the draught. I still want to burn the occaional fire but I
want to reduce the draught.

I shove a big bundle of newspaper up my fireplace to stop draughts

beware, tho, don't do what I did once: came in drunk, set a fire and
lit it without removing the newspaper !

I bult the fireback and installed the fireplace and at the time I thought
about making a flappy damper like the one displayed here

http://www.rumford.com/segflyerplan.gif

as it was I couldn't be bothered.

HtH