Wood burner reverse draw

So, knowing nothing about wood burners, yesterday I had a practical in the reverse draw effect!

It was a warm wet day and I was bored so thought I’d light the stove for some practice before winter sets in. It’s a new stove that I’ve lit once before. On that attempt it did fill with smoke upon lighting, but then sorted itself out.

Yesterday I lit it, it filled with smoke, started oozing smoke out of the stove with it’s door closed and filled the house with smoke.
I mistakenly opened the door to try and sort it making things much worse and setting fire alarms off!!!

So, it’s warm and raining again today, I’ve all my windows open to vent the house. Do I risk lightning the stove again?????

Does lighting a couple of bits of newspaper to warm the flue and change the draw direction actually work?

Also, the clean glass front if the stove was no longer see through and covered in sooty deposits, is this normal?

Yes. If you don’t have a good draw for whatever reason then you need to light it slowly, start with just a couple of bits of kindling at a time until some heat builds, its the heat rising that will start the draw and once its going you’ll be fine. It also helps keep the flue clean even when the draw is good as it warms it before you pump it full of smoke so you don’t get too much condensing on the flue.

100% warm the flue. Cool air will fall down it.

Also in those circumstances try closing the door to the room the stove is in, it can stop air falling down the chimney

Make sure the wood is utterly dry

The glass is sooted because the stove hasn’t run hot enough. Generally it’s a sign that it’s shut down to hard and needs more air. The soot will burn off when run hot, but yo can clean it with damp newspaper dipped in wood ash and rubbed on the glass. Then poish of with dry newspaper or kitchen roll. Or you can buy glass cleaner

Edit if it’s a new stove you may need to get it up to a hot temperature to cure the paint. This will stink the first and maybe second time you do it, then it’s done.

I lit a few bits of newspaper first…. AND IT WORKED!!!

I now have nice flames lapping at the log and managed to not recreate a smoke chamber in my lounge!!!

Thanks

Does lighting a couple of bits of newspaper to warm the flue and change the draw direction actually work?

Depends how cold the chimney/house is. If it’s just “not warm” and still ok outside (well above zero) it’ll work fine. If it’s -10, maybe not. I sometimes pop a couple of 8 hour candles in the fire before i go to work. They pretty much only generate heat and light, no risk of smoke going anywhere, gets the chimneys nice and warm.

Also, the clean glass front if the stove was no longer see through and covered in sooty deposits, is this normal?

Nope, it’s burning badly, needs to get hotter and draw a shed load more air through. You might also need to give it a scrub to help, damp newspaper works well.

Then poish of with dry newspaper or kitchen roll. Or you can buy glass cleaner

You don’t need to clean it. Wipe the worst off with a damp kitchen roll and the fire will do the rest for you. If it doesn’t go away you’re not using dry enough wood/have it shut down too much.

One thing to remember is at the end of the period of use open the vent(s) and burn the remains off hard, don’t shut it down so it ‘stays warm’.

Ive had this before.

When lighting the Raeburn, sometimes the smoke would come back down and into the house and whatever you did it wasnt happening.

Im not an expert so just relaying what others told me (like a sweep). Speaking to folks, they said about sometimes the air pressure outside is greater than the air pressure inside the house, and the reverse flow happens. Where normally inside house pressure is greater than outside, then the smoke rises. They also said it can happen during weather inversions.

Long story short, there were some days i couldnt light the Raeburn and had to wait for the next day…..

Also, if its a new stove, depending on the chimney construction, it might be damp as well. That really doesn’t help!
When mine was installed it had a new clay liner that was dried enough to use, but still contained moisture. Needed a couple of runs to get the last dampness out of the clay.

Some new, modern stoves which meet the clean burn regs are a PIA for this. I’ve got a small one in my study that I ultimately ended up fitting a fan to the top of the flue. It’s an externally routed twin-wall flue with a couple of bends and it is virtually impossible to light without smoking out the house on a still day. Even had the manufacturers of the stove out to check it over as I was so hacked off with it. The older stove we have in the living room is no bother at all.

Slightly off topic but if you eat pistachio nuts, keep the shells, they are great kindling.

Ours did the same trick once, filled the living room up to around knee-height cold smoke, it looked like 80’s TOTP dry ice. Turning off the extractor fan in the kitchen helped to get it drawing back in and up.

Yep turn off any cooker hoods and bathroom extractors etc before lighting.

If it’s burning correctly not only should the glass stay clean but the firebricks inside the fire will also be pretty clean.  Mine sometimes soot up a bit during lighting but once up to temperature, if things go black I know something is wrong (firewood or vents)

The inside was well sooty, I was using some old wood that’s been sat around for years. The newly purchased bag of kiln dried and the 1m3 of seasoned burn much better.

Lots of good info here! We’ve just moved into a place with a multi-fuel stove but not lighting it until serviced as every room in the house has soot on the wall/ceiling. The previous owners weren’t the sharpest tools in the box, so I’m taking all these tips on board to hopefully do a better job

If you build the fire in reverse to start with ie- logs at the bottom, kindling and fire starters on top it will start better as well.
Google Scandinavian log burner lighting to get the idea .

The old wood should be good unless it’s been left somewhere unvented i.e a lidded dustbin.

If you have a multifuel and only intend to burn wood, see if there is a conversion kit.  I sold all the griddle, fret and ashpan for more than the cost of the wood conversion kit and there is considerably more space for large logs now.

I find opening a window a bit during the lighting phase helps a bit, until the fire is  well lit and you hear the draw of air happening.

This may depend on window location?

But yes, learnt the hard way like you did!

Smoke alarms going off!

My top tip is to go to Home Bargains and buy some of their bagged wood. Its a birch from someone called woodfuel or something like that. Honestly for £5 a bag its like rocket fuel. Its super dry (or at least the stuff near us is) and hence burns really well, and you get a decent bag for your fiver. Even if you buy in bulk, or like me make your own, having some starter wood that you can store indoors  and use just a half log at a time makes all the difference to getting it going right, quickly.

So, knowing nothing about wood burners, yesterday I had a practical in the reverse draw effect!

TBH it’s not necessarily reverse draw…. just NO draw – so the smoke comes into the room.

One of our stoves goes into an unlined external chimney which occasionally doesn’t draw well when it’s cold and there’s no wind.  Once I’ve got a little heat into it it’s fine as it’s also pretty tall so normally has great draw.

The only exception is when the crows have been building a nest in it – I then have to get the drain rods out and pull out a wheel barrow full of sticks, leaves and other crap.  Like I have just done today.
It’s getting a bird guard on it later this week though as we’ve got the scaffolders in.

If you build the fire in reverse to start with ie- logs at the bottom, kindling and fire starters on top it will start better as well.

This 100%.  Any other method is just wrong.

One of our stoves goes into an unlined external chimney which occasionally doesn’t draw well when it’s cold

I had similar. Our stove was shit and smokey and generally rubbish. In the end we fitted a stainless liner and it worked infinitely better.

I can’t believe I put up with a supposedly 5 KW made in England somewhere stove for ten years, useless it was

I’ve now got a Morso inset, I put a new liner in with pumice around it and the flue to insulate, lights so easy with firelighters not paper, occasionally the door open a smidge to get the flames leaping but when it’s burning away the heat is immense, controlled by how much wood you put in. Hardly any ash and wood cut to 450mm long

Buy yourself a Stihl moisture meter to check your wood

In the end we fitted a stainless liner and it worked infinitely better.

Yeah, our other stove has a liner and it’s always fine.  The unlined chimney is, because it’s so tall, only occasionally poor and even then it’s fixed within a minute or two.
It’s used pretty much once a day in the heating season so the chimney doesn’t really get a chance to cool down so there’s always some draw.

I’m yet to feel the love of wood burners, I’m really trying because apart from looking nice it saves me using any gas, but this thread sums them up…

We’ve got a PM2.5 monitor in the kitchen. Sometimes when we light the stove it never goes over 20, others it’s at 100-120 no matter what we do. It’s a modern, Heta Scanline and supposed to burn clean but I can only presume when the readings are high we’re getting some amount of reverse draw, even when it’s burning well.

We’ve had some disastrous lightings, I think mostly when we’ve shut the door too early. We have an external air feed too, but sometimes it just seems to burn much dirtier than I’d like.

We have an external air feed too, but sometimes it just seems to burn much dirtier than I’d like.

We have clearview stoves. They do an external air feed but they advised me against it as you are pulling potentially very cold air into the stove from outside.

Even with preheating it will still be colder than air drawn from the room and this could affect the stove’s performance negatively.

IME avoid using newspaper if draw is poor. You’re just going to make a smoky disaster worse. We had similar issues of poor draw and then changed from newspaper to the straw/wax lighting sticks. Not had an issue since enough heat from the firelighters and kindling. Newspaper doesn’t do same when draw is poor.

I can’t believe I put up with a supposedly 5 KW made in England somewhere stove for ten years, useless it was

I have 2 of them, and mine burn hot and clean. Rarely need more than a half firefighter and to be ignored for 10 mins to be fully up to heat.

They do an external air feed but they advised me against it as you are pulling potentially very cold air into the stove from outside.

We read mixed reviews. A few variables mean it’s difficult to say with any certainty, but it seemed to make no difference after we added it, for good or bad.

A few variables mean it’s difficult to say with any certainty

Theoretically a good idea.

I had great success yesterday using a few bits of newspaper first, we’ve had days of torrential rain here so I had a lazy day watching the flames and heating the whole house through. Some of the old wood I have is reluctant to burn with much flame, the newly purchased seasoned stuff goes up great. A really nice day hiding away from the rain with coffee & cats.

Sometimes when we light the stove it never goes over 20, others it’s at 100-120 no matter what we do.

My monitors (2x) get higher (much higher) when i open the back door in pollen season… Most of the time between 15-35 with the fire running, sometimes 100+ with the back door open!! (And the fire not running)

Speaking to folks, they said about sometimes the air pressure outside is greater than the air pressure inside the house, and the reverse flow happens. Where normally inside house pressure is greater than outside, then the smoke rises.

How well sealed is your place!

I’ve ripped out my open fire, and we’re having a log burner installed Monday. I’ve been saving wood all summer from work for kindling. Pretty excited!

It’s cheating but a hairdryer blowing air into the flue before lighting has had good effects, as (not cheating) has just leaving the stove open for 30 minutes before lighting to let any cold air fall out – that’s for the cold overnight but a bit warmer now days.

Sometimes draw problems can be outside the house. keep an eye on trees etc. in proximity to the flue. Trees have this way of getting taller.

It’s cheating but a hairdryer blowing air into the flue before lighting has had good effects, as (not cheating) has just leaving the stove open for 30 minutes before lighting to let any cold air fall out – that’s for the cold overnight but a bit warmer now days

This is quite interesting. I have grown up with open fires and then wood burners and there are lots of gadgets and tricks I saw when I was a kid. One was a special hot air blower on a stand that you pointed up the chimney and switched on. After 5 minutes you pointed it at the kindling and it set it alight. It was good but had that 1950s bad health and safety vibe about it!

Letting the cold drop out I have never tried so might experiment with that. I have done something similar, when it’s been really cold ie frosty out, shutting the door of the room the fire is in will reduce the downdraft as the room can’t empty the cold air as quickly. Only seemed to work on very cold nights though.

In my experience, stoves with top exit flues have generally better draw than rear exit ones. It’s not hard and fast but I think the rear exit has a slightly more convoluted route.

Current lighting technique my Danish friend showed me and is two logs front to back with paper between. 2 kindlings span the paper like a bridge, then 2 more the other way like a grid. Log on top. I light with a 5 second blast with a blowlamp, instant paper ignition then immediately shut the door with all vents open.

Some newspaper isn’t as flammable as others. Ironically the guardian is excellent for wood burner lighting.

Birch is my favourite timber, we collect and process everything ourselves and it is probably gives the best burn vs processing effort. Easy to split and dries relatively quick, good heat. Everything down to finger diameter is collected and dried. Smaller gets chipped and composted.

One was a special hot air blower on a stand that you pointed up the chimney and switched on. After 5 minutes you pointed it at the kindling and it set it alight. It was good but had that 1950s bad health and safety vibe about it!

:D There’s a long black streak across the oak floor in my dads old place where one fell over and scorched the floor…

I use a blow torch. Quick blast to warm the flue if needed then light the kindling.

OOOh kitchen blow torch – good idea have one of those in the cupboard!

I generally use the white block chemical firelighters as I find they give of a big burst of heat quickly, to get teh draw going.

I also tend to put one in amonghts the kindling, and one on top of the log stack in the firebox to get teh draw going.  Seems to work most of the time, but will definintley be considering a blow torch next time its properly cold!

I get a flat bit of wood and stick that on the ash. Make a wee stack of kindling around a fire lighter (the shavings and wax ones) then stuck a small log on top.

I only got a smoke filled living room once when I used to use newspaper on one of those oppressive cold damp still days where the air lies heavily on the roof smothering all joy. I feel newspaper burns quick but in doing so doesn’t generate the heat or convection current a fire lighter does.

One of our stoves goes into an unlined external chimney which occasionally doesn’t draw well when it’s cold

I had similar. Our stove was shit and smokey and generally rubbish. In the end we fitted a stainless liner and it worked infinitely better.

What did they suspend the liner off the top of the chimney with ?

I always had problems getting my external flue wood burner going on very cold days.

Tried the blow torch. Wasn’t powerful enough.

Solution was 2 sheets of newspaper very loose and light them with the stove door ajar.

It needed a quick blast of heat to remove the cold air in the flue.

My other stove had a liner up the chimney insulated with Leca. That was so easy to light.