Well I'm going to be about =A3400 out of pocket because I haven't been cleaning my chimney properly.
It was built a bit over 20 years ago with an 8" clay liner. The mistake I made was to sweep it with the ball, rope and brush I'd inherited from my father who had used it to sweep large old fashioned stone flues. I was always a bit suspicious it was too large a brush as I was always struggling a bit to get it to reverse and come back up again. So the nett result was that accumulatively over the years the bottom section was not getting cleaned - even when I changed over to rods and a smaller brush.
And of course the crisis arose when it finally wouldn't let any smoke through at all !!
Call in the professionals - "It's blocked, sir - you've not been sweeping it properly".
"Yes I know - and I plead guilty, but haven't you got a drain cleaner like thing to clear it?"
These do exist but are not recommended for clay liners as they will just chew through the liner where there is a bend. So the only solution was to break into the flue from the room and clear it out. Result two large sacks full of soot and a replastered patch on the wall, that "her-indoors" is now going to use as an excuse for re-decorating the room.
One thing I did get told was that if you are burning wood, it is best to sweep the chimney quarterly (obviously with the right equipment). The professionals do not rate the powder that I bought to crystalise the creosote. Better to sweep regularly they insist.
I would certainly like to put in a plug for Paul Maclenachan near Edinburgh; anyone with chimneys problems in the area, look him up in the Yellow Pages - you won't be disappointed, he was excellent.
Rob