Below was the resolution to their problem:
Hello, I just thought I'd post an update and the conclusion of my fireplace saga, in case it's of use to the next person looking for fireplace help.
First we called the fireplace guys back, who said the old damper maybe wasn't working after all and also found more suicidal squirrels. They removed them, and installed a new damper with cage.
There was no improvement with the draft, only it was more smoke and less foul. We were considering our options and were going to call and give the chimney guys hell.
We decided to get one of those chimney pillows as a temporary stopgap until we could get the problem solved once and for all. In the meantime, we noticed that bricks on both shoulders of the fireplace were loose and there was lots of cracked mortar and moss. There was no direct evidence that this was causing the draft - no air coming out, the lining was intact under the bricks, that we could see at any rate. But it was clear that this was only going to get worse if water and plant life kept getting in and we didn't want bricks to start falling off the chimney.
So hubby bought a chimney pillow and some sort of masonry cement caulk
and glued the loose bricks and filled in the large cracks.
Instant cure. We weren't even trying to fix the draft problem, and I still don't know exactly where the leak was coming from, but this fixed it. We still get some smell when the heat or certain fans are on, but that's expected. The chimney baloon will fix probably that.
This was their initial posting of their fireplace problem:
I am having an ongoing fireplace saga that I am hoping the good folks here can help me with. We just bought a townhouse this fall, built in 1973, with a fireplace. To make a long story short, here's the timeline of what's been going on.
Fireplace was sealed (opening covered in plastic wrap) when we bought the house. We unsealed it. Fire burns fine, but smoke smell and strong draft pours in when not in use.
Did some research, found out about negative pressure - the house seals like Tupperware so this makes a lot of sense for us. We opened a window in the basement next to the furnace. No change.
Brought in a professional to do the sweep/inspection that we should have done in the first place. He cleans out the chimney, fixes the damper that was apparently never closing, removes an interred squirrel of great antiquity. He also replaces the crown and says water has been leaking in and causing mold for a long time.
The draft problem is now completely fixed, but the strong smell still fills the living room and creeps around the house from there - a foul, wet, moldy-sooty smell.
So I see two angles here. One is trying to improve the condition that is still causing the fireplace air to come in. The other is dealing with the nasty smell in the fireplace. But this is so far out of my realm of experience, I am not sure. I don't mind a little soot smell, I understand that's part of owning a fireplace, but you can't stay in that room and breathe without opening a window.
What should we do? Will a steady regiment of fires and ventilation improve things over time? Is there something more drastic we will need to do? Is there something that might kill the mold we suspect is up there? We think the fireplace may have been sealed from the inside but exposed and leaking to the outside for the 12 years the previous owners lived here. Is there an air-tight plasic cover or something we could fit over it when not in use?
Any help would greatly be appreciated.- MK