Smoking multi fuel stove

Oldman50

Hi and thanks for letting me join. We have a big problem with our stove to the point we can’t use it. This is the problem. It was burning fine then one night it just started to fill the room with smoke to the point where a flame wouldn’t burn long. We had the chimney swept and the problem is still here but when he swept it he found a small piece of liner so there might be a hole. Could that be causing the smoke to not be drawn up the liner. I’ve tried bone dry wood and kindling all just smoke. 

doodling

Hi,

Whilst it is absolutely not recommended to use a stove with a liner with a hole in it (due to the risk of carbon monoxide poisoning, possibly in other rooms in the house), even in that case then once there is a column of warm air in the liner  / chimney then it should draw, providing there is no obstruction, unless the chimney itself is very leaky.  If you've put a good wodge of newspaper in the stove and lit it and smoke is still coming into the room 30 seconds later then you have a blockage.

Did your chimney sweep go outside and check that their brush stuck out the top of the chimney once they got to the top?

The other option is that there is some kind of kink in the liner which opens up to let the brush through but closes otherwise.  The only way to be sure of that is to get your chimney sweep to use an endoscope attachment on their poles to inspect the liner (assuming your sweep has one - you may need to phone around).

I'm assuming that there has been no change to the level of ventilation into the room with the stove - is that right?  Nothing that could affect air flow in the house like new double glazing or increased use of an extractor fan?

Oldman50

Thanks for the reply. No there’s been no changes to anything for years now. When he cleaned the chimney his mate was out side and said loads of black stuff came out the top. He had no trouble sweeping it. When he lit it after it smoked a bit so he swept it again and some Woolley type stuff came out which I assumed was insulation in the liner. To get someone to stick a camera up it is 300 euro so we are waiting on one for a phone just to have a lookie

Ectophile

Another thing to check is the stove itself.  I found that my stove wasn't burning right, and filled the room with smoke.  I called out the sweep, assuming that the local pigeons had blocked my chimney.

It turned out that a blanking plate had fallen off the back of the stove.  That left a clear air path from the back of the stove and up the chimney.  So the air didn't bother going through the combustion chamber any more.

Oldman50

Ectophile said:

Another thing to check is the stove itself.  I found that my stove wasn't burning right, and filled the room with smoke.  I called out the sweep, assuming that the local pigeons had blocked my chimney.

It turned out that a blanking plate had fallen off the back of the stove.  That left a clear air path from the back of the stove and up the chimney.  So the air didn't bother going through the combustion chamber any more.

Thanks for the suggestion but all is well with the stove. It exit from the rear and only recently had a new baffle plate as it’s a boiler we currently have no heating. Even the chimney sweep couldn’t understand why it is doing it

Ectophile

If the chimney is straight, you should be able to look all the way up it with no obstructions.  The easiest way is to remove the register plate from the top of the stove, then hold a mirror so you can look up the chimney.

Oldman50

Ectophile said:

If the chimney is straight, you should be able to look all the way up it with no obstructions.  The easiest way is to remove the register plate from the top of the stove, then hold a mirror so you can look up the chimney.

I bought an endoscope off the internet but didn’t do the job. I have a car inspection mirror I’ll try that tomorrow. I lit a fire last night and the fire lighter only just caught and it billowed out smoke even from the vent so had to throw a mug of water on it to put it out

Effician

I'm presuming that the ventilation in the house hasn't changed ( you,ve not blocked any external wall vents etc ) & you say the stove is in good working order , all that remains is the flue.

If the flue liner has ruptured & presuming you have vermiculite or similar insulation this will flow into the flue liner & gather at bends or rough patches, easy to push through when sweeping but enough to block air flow.

How old is the liner & what grade was it ? maybe just time to replace it.

Oldman50

Effician said:

I'm presuming that the ventilation in the house hasn't changed ( you,ve not blocked any external wall vents etc ) & you say the stove is in good working order , all that remains is the flue.

If the flue liner has ruptured & presuming you have vermiculite or similar insulation this will flow into the flue liner & gather at bends or rough patches, easy to push through when sweeping but enough to block air flow.

How old is the liner & what grade was it ? maybe just time to replace it.

No we’ve made no changes to the ventilation in the house. When they swept it the second time a couple of handfuls of wool like material came down which I can only assume was insulation. There’s only one bend at the bottom of the liner at the back of the stove. I tried using a mirror to look up there but it’s so black and so is the cover at the top I couldn’t see anything and the cheap endoscope was useless. 

Not sure how we’re going to find 1-1.5k to get it replaced. Oh it was just the cheap corrugated type as obviously the installer wanted to make as much profit as possible 

Effician

You say the stove has a boiler for your heating, i'm guessing you burn a fair amount of (hopefully ) smokeless briquettes mabye with a mixture of wood. If my supposing is correct you really should be looking at the higher end quality wise of flue liner ( 904 , 904l ) to deal with the increased corrosion risk from sulphuric acid by burning smokeless with lower flue temps due to boiler , burning wood with smokeless just adds more moisture to the sulphur released by the smokeless fuel making matters worse.

It doesn't make sense to go cheap on a liner as an extra few hundred £'s on a good un is only a small portion of the fitting cost. Unfortunatly it looks like yours has had it if the sweep has pulled out some ( presume rotten) liner & insulation .

Oldman50

We only ever burn timber blocks. We bought a load for n October and they burnt fine and then a different load on January whether it was coincidence or not but that wood wasn’t particularly dry and a few weeks or so after was when the problem started. We don’t burn briquettes as they produce too much ash. 

Unfortunately we’re not financially well off and can’t afford the better quality liner if we could we would. If the liner is bust/rusted would that affect the draw for the smoke? I’m guessing it would.