J
jontris
Well, it's definitely rain water. This only happens when it's raining. I've also proved it's not coming along the outside of the flue. A cloth tied round the flue as it enters the boiler remains bone dry. It's not coming down the gas side. I've got one of those directional extensions pointing downward. It must be rain water flowing back down the flue on the air side. Properly installed where would this water go?