Multi Fuel Stove - Total Cost Query

How many people on here with stoves have soot boxes fitted ? If you don't how do you clean your chimney?
 
Very good question because a lot of people appear to forget that with a stove the chimney needs to be cleaned at least once but recommended twice to three times a year. Many stoves allow you to remove the baffle to get access for cleaning, others require a soot box or a tee off the flue to allow access, on some a soot door in the flue usually at a 45 degree bend will suffice. That said there are thousands of stoves installed without any consideration to cleaning the chimney / flue.
 
Just to play the Devil's advocate :

There is a line of reasoning which goes like this :

- Clean wood burning stoves

- Are clean because of wood gassification burning

- And so there should be very little creosote etc going up the chimney ( when compared to an open fire )

- So why does chimney need to be cleaned more often than an open fire rather then less often ?

I wonder what an experienced sweep would have to say on this
 
The more efficient the stove the lower the flue gas temperature is which on entering the flue will cool and can condensate, very few people allow their wood to dry to less than 20% moisture content so there is always some moisture in the wood. Stoves can not reach the temperatures required to burn off all of the nasties which when combined with condensate forms creosote. There are very few stoves that gassify (inverted burn) I only know of one though I'm sure there are more. The open fire being inefficient allows around 80% of the heat to escape up the chimney resulting in flue gas with substantially higher temperatures, on the plus side less chance of creosote build up. Stoves are often run with the air intake closed (shut down for the night etc) without air we have less burning so lower flue gas temperature which means the gas will condensate before it reaches the top of most chimneys so more creosote. I Am Not a Sweep ;)
 
Peter C said:
.................. There are very few stoves that gassify (inverted burn) I only know of one though ....................
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Thats very interesting

I'd formed ( jumper to ) the view ( for no go reason or basis in fact ) that any stove claiming circa 80% efficiency or better or 'cleanburn' was doing it.

How can I establish which stoves gassify and which dont ?

Peter C What is the model that you know of that does gassify ?
 
olddog said:
I wonder what an experienced sweep would have to say on this
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It was a sweep that told us that we shouldn't put in a solid fuel stove without a soot box. We never put in a stove in the end because we couldn't get consistent advice on various aspects of stoves despite talking to several people such as suppliers, installers and the sweep. Some told us we needed to get the existing chimney lined, the sweep said we didn't - who do you believe? One installer told us we would have to put some type of heat deflector material on the underside of the top part of the fireplace or it would warp - a guy selling stoves said we didn't need to do that ! I have read most if not all of the threads on AAM about stoves and there is rarely if ever a mention of how you access the chimney for cleaning when a stove is fitted. Safety would be the most important issue for me regarding stoves - I would rather stick with the open fire and get the chimney cleaned once a year than get an efficient stove, have no chimney access and end up with a fire in a few years.
 
Peter C said:
Many stoves allow you to remove the baffle to get access for cleaning, others require a soot box or a tee off the flue to allow access, on some a soot door in the flue usually at a 45 degree bend will suffice.
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Very useful info - Thanks.
 
demoivre said:
Very useful info - Thanks.
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I am not surprised at the different advice you received, the sweep may like a soot box because he finds it user friendly, soot box's were often fitted outside with solid fuel cookers and made them very easy to clean, even the one's beside the cooker saved a lot of time so for the same fee the sweep could have it easy or more difficult, which option would you choose?
You go into a shop and most will tell you what you want to hear, their job is to sell the stove so why add confusion and more cost after all if installation is too expensive you may not buy the stove. Some installers will not tell you that you should line the chimney especially if you are fitting a small stove with a 5" spigot into a clay liner that is 8" diameter, sometimes they don't know you should and others do not want to price themselves out of the job.
My policy is tell the people the best way to get the best value from their purchase, I do try to look into or speculate how much money is in a customers pocket, many leave without buying but a lot return (some 2 > 3 years later). I find the majority of people want value for their money, that does always mean cheap in fact it very seldom does.
 
Peter C said:
I Some installers will not tell you that you should line the chimney especially if you are fitting a small stove with a 5" spigot into a clay liner that is 8" diameter, .
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what does this achieve? I am close to fitting a stove but had not considered this. I will be fitting the external soot box though.
 
Olddog, The stove I know of that is a gassifier is called "Walltherm" efficiency around 93%, not sure if I am allowed to post a link if you would like to know more send me a P.M. Many of the better quality stoves on the market have tertiary air as well as the primary and air wash. When the tertiary air is working it can appear like a gas ring forming jets of flame burning off much of the carbon that remains in the smoke.

MrKeane, The stove is tested for efficiency based on the fact that the flue is 5" which is why the spigot is 5" (or 6" / 7" as the case may be). A 5" flue opening into an 8" flue is akin to a river 5 feet wide flowing nicely then somebody opens the river to 8 feet wide and the river flows to a trickle unless there is away to improve the flow where the river rises.
When the stove is installed using the correct flue it allows the flue gas (smoke) to rise through the flue pulling the correct amount of combustion air into the stove. When the flue suddenly widens the flue gas which is at a much lower temperature than the existing flue was designed for (Eg the open fire the stove replaces) it can hang in the flue causing it to condensate. Of course many stoves appear to work fine but they are pulling in more combustion air to compensate for the wider flue therefore using more fuel. The most important item is the low temperature of the smoke in the wide cold flue, heat meets a cold surface and you have condensation which combined with the unburnt carbon causes creosote to form on the flue which causes chimney fires.
I understand how many people can be surprised that cost of fitting the stove can often be as much as three times the price they paid for stove especially the cheaper models. I expect as more people draft proof and insulate their homes to higher levels we are going to hearing of stoves that don't work properly and a much higher rate of chimney fires due to condenates in the flue. I also expect insurance companies will be investigating the cause of the chimney fires and will refuse to pay out on claims where good working practices have not been followed when installing stoves.
 
I can anyone tell me how to do a DIY instalation of a flexi flue?Well iv made an attempt at getting it down the chimney of a 150 year old two story house and can get it in 4 metre of the 8 but am failing to get any further.It seems to be caught in a corner.We tied a rope to it and were pulling it down aswell as pushing from the top but no success.Is there any nacks that i'm missing?:confused:
 
Hi, It is not unusual in very old chimneys to have the flue narrow down in places, one we did actually reduced to about 5" diameter for 3 feet !
Many of the 150 year olds were formed using brick mid feathers and parged (kind of plaster) again not unusual to have ledges, did you clean the chimney before you started ? Besides being necessary it can also give a good idea of how the flue is formed, example resistance at 4 metres, you could try to pull / feed it up the flue we have used a steel ball and even had to open the chimney breast, sorry can't say there is an easy way.
 
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