Hi OP,

A couple of things going on:

1.  Excess soot is coming out of your chimney - you need to have that properly cleaned.

2.  I would be checking the moisture level of your wood.  I know you say it's dry, but if I had a dollar for everytime someone said that and it simply "couldn't be the reason for my logfire problems", I wouldn't have to be a chimney sweep no more and could retire.  Dry wood is 20% moisture or less.  Yes the Good Wood Programme says 25% is 'dry wood', but I'd go further and say 15% moisture is what you should be aiming for.


3.  You have old enamel steel flue - I wouldn't be surprised if this was worn out at the flue joins and is leaking smoke and hitting the inside of your outer liner, breaking down the galv in it and rusting.  The other thing is was the upper section replaced, or was it extended?  If it was extended, was the flue also extended with it?  Again, smoke and gas should only be coming out of the inner flue - the outer galv liners are for insulation only.

This is what your flue system should like: outer 250/300mm liner, inner 200mm liner, 150mm s/s flue.