What am I looking at here?

[oldkettle]

Hi,

 

I have finally got an engineer to disconnect gas from the fireplace we have. Since we are planning to remove fireplace completely when we build the first floor I wanted to "enjoy it while it lasts" and burn wood on some particularly cold and damp weekends. So yesterday I removed artificial logs and proudly put on a self-lighting log.

 

https://www.flickr.com/gp/97587014@N08/S15j61

 

It was all going well.

https://www.flickr.com/gp/97587014@N08/919W27

 

And then I added a proper log. Within 5 minutes the room was not a great place to be in. It was not full of smoke but there was enough to feel uncomfortable. The flue was definitely open - I have only figured out how to close it today  Even now, after keeping windows open for well over 5 hours, I still feel the smell.

 

So I removed the damper rod and had a closer look. Judging by the name I have managed to read - New Marathon - there is an unused back boiler behind the fireplace. One of the pipes is cut, I guess intentionally, to prevent it from blowing up.

https://www.flickr.com/gp/97587014@N08/i85w8V

https://www.flickr.com/photos/97587014@N08/30988319822/in/album-72157675531126370/

 

Since my experience with fireplaces is non-existent, can somebody please tell me why did it go wrong so spectacularly after I added wood? OK, the first log is "no-smell, no smoke" but still it was not like all smoke was going in. Is it still safe to keep using it with these special logs?

[PeterW]

Is it definitely a coal flue or has someone restricted it or re-lined it for the gas fire - did you try a smoke match first ..?

[MikeSharp01]

Yes, can you see all the way up it? If you can then its likely you have a negative pressure problem which the heat from the log cannot overcome, sometimes happens in 'funny weather'  - try a smoke test if you cannot see up it.

[oldkettle]

I can't see all the way up - it makes a turn after about 50cm+. I don't know how the lined one should look like TBH. To my eye it is simply a thick metal. It seems to get to say 25cm diameter before it turns but the turn is wide. There is a lot of soot there.

I can see the flame of the lighter getting much taller as I bring it closer to the flue. Was the same when I tried to burn the paper a couple if years ago as a test.

 

I can try part of the process from here http://www.bfcma.co.uk/smoketesting.aspx sometime, but there is no way I am going on the roof - it is not that high (bungalow) but I don't want to take any risk with the old slates. It least I should see whether the smoke gets all the way out.

 

Edited November 20, 2016 by oldkettle