Installing an open fire

cwhaley

cwhaley

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I have a wood burning stove which is efficient and does a good job of heating the home. I recently posted a new thread about installing another one in the kitchen -- reason being we have access to free timber (living near a furniture-making town).

I have been offered a white limestone surround which would look great with an open fire. Yes I know they're much less efficient but for aesthetics they're great and sitting next to it at the kitchen table in winter is just too appealing for the other half.

I have had the chimney swept and smoke tested -- sweep said it would be good for an open fire. The next job is to rebuild the top part of the chimney, straighten the flue and put a cowl on. After this though, what do I need for an open fire? I know I can just stick a fire basket in there but obviously there will be a huge draught.

Can I install a cast iron insert and back fill as was done originally? If so, does the dampener plate allow the control of air up the chimney?

Just after a bit of advice as the process as this is totally new to me.
 
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best get a HETAS in - i dont know because i've never installed a damper but it might be tricky?
 
Update if anyone is interested. I had the chimney sweep back to examine the state of the chimney and all was fine. In the end we did go for an open fire which I've posted some pictures of below. I built a brick hearth and sourced a cast iron insert which was put into the opening. I fixed it into place and sealed around the edge then built a surround using old ply and some lengths of architrave and beading I had in the shed.

The new problem is that when lighting the fire, the smoke exits the chimney pot and a lot of it sinks down the front room flue pumping smoke into the room! This only happens when the stove is not lit and the flue cold. Not sure how to stop this other than by putting a taller pot on?

thumbnail_F436CAAD-987D-4AE9-B94C-DD0F6A71DDB7.jpg thumbnail_IMG_0066.jpg
 
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lostinthelight said:
Does the room the fire is in have enough air supply, if not it may be trying to suck it down the other flue?
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Yes plenty of air supply from the failing seals on the old double glazing! I have started it with the door/window open to promote a good supply but this does little to help. I think it's because the pot and the cowl on the stove flue are very close to each other at the same height.
 
how was the damper installed? who did it?

the smoke problem sounds more like a damaged flue feather (brick partition between flues) thats allowing smoke and fumes to transfer into the front room flue - this is dangerous.
any sweep worth his salt would have smoke tested your flue and many of them now drop cameras down the flue?
when you have a sweep on site it pays to have them sweep, smoke test and camera all the house flues.
do you have C0 alarms in both rooms?
 
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bobasd said:
how was the damper installed? who did it?

the smoke problem sounds more like a damaged flue feather (brick partition between flues) thats allowing smoke and fumes to transfer into the front room flue - this is dangerous.
any sweep worth his salt would have smoke tested your flue and many of them now drop cameras down the flue?
when you have a sweep on site it pays to have them sweep, smoke test and camera all the house flues.
do you have C0 alarms in both rooms?
Click to expand...

The flue damper is an integral part of the insert; it wasn’t installed separately.

Thank you. I’ll explore the possibility that the feather is damaged but my gut feeling is the proximity of the pots to each other plus the prevailing wind/outside temperature. The flue was cleaned but I didn’t ask for a smoke test — reason being I carried this test out myself prior to the installation. I got some smoke pellets from the plumber and used those. I clearly saw smoke rise from the chimney pot and nothing had come down into the front room, nor in the upstairs bedroom or loft.

I do have CO alarms and neither have moved beyond “normal”. Very good point to have these checked and working.

The chimney does need repointing and the top two courses of brick rebuilding. I also know that the flue pot for the kitchen is leaning slightly. I’m currently gathering quotes. I know the people who put the liner down for the stove said it isn’t awful but does need repair work.
 
Presumably the flues have worked together in the past so something has changed to alter things, What size liner did they install
edit, ok I see its an unlined flue
 
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lostinthelight said:
Presumably the flues have worked together in the past so something has changed to alter things, What size liner did they install?
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Yes the kitchen chimney breast hid the back boiler which was in use until the 1980s (spoke to neighbour) and the front room fire was in use until a similar period. Including the bedroom there are 3 flues in the house. They terminate at the chimney which is shared in the middle of us and the neighbour who also has 3 flues.

For the burner we used 904 grade 5” liner. The collar on the stove is 5” and is DEFRA-exempt.

If the stove is lit nothing comes down from the kitchen flue at all — it’s only when the stove is off. I’ll hold off using the fire for now and see what the roofer says. I know the crown on the chimney stack is crumbling but can’t see why this would cause the issue.
 
lostinthelight said:
Is there a liner in the open fire snd if so ,what size
edit, ok Ive reread and see theres no liner
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No liner in the kitchen no (unless you count the original ‘lining’ inside the flue). When it was swept it was clean with no blockages.
 
Just as an update, I had the open fire going last night (as a test) and after an initial haze of smoke in the front room this disappeared once the fire/flue were up to temperature.

I then when to light the stove and the smoke from the newspaper was being blown back into the room which has never happened before. This stopped once there were strong flames from the kindling going up the liner/flue.

I'm thinking this supports the idea that smoke is coming down the cold flue during lighting and initial running of the coal fire. Just a theory and I'm still having the chimney inspected/repaired.
 
With this issue it sounds like the mid feathers have collapsed. The hot gases are cooling as they rise and some is escaping and heading down the other cold flue. When the heat in both flues is higher the hot gases create a good flow so the smoke is sucked outside. If you lit one and smoke comes out the other unlit flue and visa versa then its the feathers.
 
martin hill said:
With this issue it sounds like the mid feathers have collapsed. The hot gases are cooling as they rise and some is escaping and heading down the other cold flue. When the heat in both flues is higher the hot gases create a good flow so the smoke is sucked outside. If you lit one and smoke comes out the other unlit flue and visa versa then its the feathers.
Click to expand...

If light the stove (which has a liner) while the fire is on, smoke bellows out into the room from the stove until there is enough heat present to help the smoke rise up the liner.

I’m not ruling out chimney damage at all, but if the mid feathers were breached why would smoke be pushed down the liner and into the stove? The only opening in that liner is at the very top of the chimney on the pot. That’s the only place smoke could be entering.
 
Two things you can do is like you say install a higher pot or get a top damper installed which will seal the chimney and stop it getting cold whilst you're not using the open fire.

Btw your open fire looks a cracking job , I do love the smell of a real fire can't beat it!
 
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