recently we have had a new gas fire and had the chimney changed from a brick which has been brought down to roof level and a steel flue put on.But the damp on the chimney breast has got worse ,we thought getting rid of the very tall chimney would help this.
Sue, I have recently suffered similar problem with damp stains in chimney breast in bedroom. After much hassle it was found the flournching was the problem. That is the mortar fillet that keys you chimney pots/flu etc. to the brickwork on top of chimney. We aslo took the precaution of re-pointing the whole chimney ie. belts and braces! Hope you find the cure. Tony DIY.