Category Archives: Stoves

Buckled/Broken Baffle Plates

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It almost always comes as a shock to new wood burner or multi fuel stove owners that their baffle plate (also known as a throat or deflector plate) is classed as a stove ‘consumable’ and is therefore NOT covered under their stove warranty in the same way that most of the other components are.

This is because baffle plates are positioned at the top of the fire chamber specifically to deflect flames and heat back into the stove instead of letting them go straight through the flue system. And is partly why stoves are much more efficient at delivering heat to your room than an open fire.
However, it’s also why even on top quality stoves, baffle plates tend to burn out.

The Main Problem

Baffle plates are positioned at the hottest possible part of the stove and take the full brunt of the very high temperatures day-in and day-out. So whether your baffle plate is made of traditional cast iron, heavy steel plate, stainless steel or vermiculite board, you will eventually have to replace it.
How often this needs to happen depends on the type of fuel you burn, the size of the fuel load and how you burn your fuel.

Some stove owners can burn through their stove baffle plate in a matter of months and conversely some owners can make theirs last for years. A baffle plate on a boiler stove for example, will not tend to last as long as a baffle plate on a non-boiler stove. This is simply because boiler stoves generally need to be burned ‘harder’ over longer periods to maximise the heat to the hot water, especially when there are lots of central heating radiators connected to the system.
***As a matter of interest, smokeless mineral fuels (eg Anthracite Ovals) do not have the same flame height as an equivalent wood log load and can therefore be easier on a boiler stove baffle plate (but not necessarily on your CO2 emissions or our faces).***

The Consequences

If you regularly need to replace your stove baffle plate then you should review how you operate your stove by referring to your owners manual. It should contain advice on recommended fuel types and fuel loads, as well as instructions on how to effectively operate your stove. Quickly burning out a baffle plate means that you are probably not only wasting money on replacement baffle plates but also wasting money on fuel for sure.

***Chimney sweeps need to be able to remove the baffle plate so they can use the power sweeping equipment and clean effectively. *** If it is buckled and cannot be removed then I am in the unfortunate situation of having to charge a call out fee and you will need to call your installer out to remove & replace it.

Damaged baffle plates are increasingly more common these days, (which is one of the reasons for writing this article) creating speculation on the quality of metal materials nowadays. Also, often the installers fail to ensure the customer is sufficiently educated in the use and maintenance requirements of their appliance in the first place. Mostly though, it is users over filling beyond the stove load capacity.


The Cure

It is often the case that you are over loading and over-firing your stove and producing excess heat which is wasted through the flue system. An easy to use magnetic flue pipe thermometer will help you to monitor your flue gas temperature and can clearly indicate when you are over-firing your stove.

In my opinion a flue pipe thermometer is one of the best, ‘value for money’ stove accessories you could buy. It helps you to maximise the efficiency of your stove and also alerts you when your stove is potentially dangerous by being over or under fired.

It is very easy to abuse a stove and burn out a baffle plate within a single heating season by simply ignoring the manufacturer’s recommended fuels and operating instructions. Ergo, it’s also easy to see why most manufacturers now exclude baffle plates, fire grates, fire fences and glass from their normal warranty terms.

Figure 1 : Warped , corroded and finally broken Baffle plate

Figure 1 above shows a burned out cast iron baffle plate which is about three years old.

The owner used mainly softwood (it was free) which required a substantially bigger fuel load than the equivalent hardwood load needed to generate the same heat.

***This meant that the fuel and flames were too close to the baffle plate so the extremely high temperatures which were created, caused the baffle plate to warp and eventually fail (there is NO middle left).***

That particular stove had a rear fitted flue and it wasn’t until the owners noticed the flue pipe was glowing red that they realised they had any kind of problem.

Fake News and wood burning stoves

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Wood burning stoves have been unfairly targeted by blogs, the press … just about everyone lately and are being painted in a very negative light. The reality, which in my view is very different to that portrayed in the press of late. So i will attempt to address the matter somewhat here in this post.

Firstly, wood is one of the only truly renewable fuels but yet is often compared to diesel due to some of the particles that are emitted when burned. Diesel is a fossil fuel derived from crude oil and although some particles are emitted during burning wood (in a bad way & in old appliances) I’m pretty sure that diesel does not produce a major percentage of the worlds oxygen like trees do.

With the massive deforestation that has takes place in recent history, ethical log suppliers are now rapidly planting trees which will help safeguard our future generations. Those same planted trees will store the carbon released from today’s log burning making the cycle neutral.

Statistics can be a funny thing and are often taken on an annual basis. As we know, the wood burning season in the U.K. is relatively short beginning late September through to the end of March/April. During the rest of the year any measured pollution does not come from wood stoves. Ironically it is the summer months when the dangerous carbon dust particles are often at their highest levels.

As far as i am aware, there are no statistics specific to wood-stoves published in the U.K. with regards to air quality or pollution. Instead statistics are based on all domestic burning of wood and its’ derivatives and includes open fires, camp fires, pizza ovens, BBQ s and bonfires. The last two in the list are some of the very worst pollutants and yet somehow only wood burning stoves are being attacked.

I understand that there is a genuine problem with the use of some wood burning stoves. There are four main issues that chimney sweeps must advise on; in regards to wood burning in order for clean combustion.

1. Moisture content and quality of wood logs.
During the combustion process it is necessary for there to be high enough temperatures within the firebox in order to burn the majority of the carbon particles. When excess water is present, the energy which would normally ignite these particles is instead utilised to evaporate the water contained in the log. This causes much of the fuel contained within the wood to not burn and is instead emitted as smoke.

**I personally always suggest you only burn sustainably sourced (preferably hardwood) logs with less than 20% moisture content. Using wood-sure logs will help as the checks have already been done but you can always invest in a moisture meter and check for yourself.

2. The way the end user burns their stove: specifically the dangers of slumbering, over-fueling or under-fueling.

As is often with many ‘old school’ things, some strange ‘old wives’ tales have developed about how stoves should be used. It has unfortunately become a ‘normal’ practice for many to fill the stove with wood and then reduce the air supply in order to make it last through the night. The process is referred to as slumbering and it is very bad indeed with regards to air quality and pollution. Not to mention the safety and functioning of your stove +/ liner.

To use layman’s terms; if you remember the Bunsen burners in school science labs. When the air hole on the side is open the flame is sharp, blue and clean. But limit the oxygen by closing that hole and the result is a flame that becomes lazy, yellow and soots up whatever it touches.

This yellow, colder flame in also inherently more dangerous because the levels of carbon monoxide are very much higher in a reduced oxygen environment (combustion is incomplete). Limiting the oxygen results in a much lower combustion temperature meaning many volatile components do not burn when slumbering, therefore it is far more polluting.

Like all hydro carbon based fuels wood needs oxygen in abundance for all of the gasses emitted within the fire box to combust completely and cleanly. Limiting the air does not limit the gas released by the logs it only limits how much of the gas will burn.

***Users are advised to always burn the quantity of wood that the stove was designed to use and with primary & secondary air controls open enough to provide moderate flaming combustion. [This is when the entire window is filled with rolling fire and no smoke is seen but not so much that the flames can be seen sucking up the chimney.]

3. The third problem relates to the age and efficiency of the stove. It is a fact that older stoves are very much more polluting than newer, more modern appliances. ****Consumers should be advised that new appliances will save on fuel, give more heat and allow much better quality air that we breathe.

4. Finally, servicing and maintenance.
It is understood that regular sweeping of chimneys, cleaning flue-ways and servicing appliances are all essential for continued efficient combustion. Chimney sweeps should ideally ensure that stove servicing and education is a part of their repertoire in order to bring this essential service to their customers.
*****Indeed, my own advice is always to burn clean dry logs (<20%). Do NOT slumber and use the correct amount of fuel in each fill. For what it’s worth i also try to suggest clients update outdated appliances where necessary and should get our sweep service up-to two times per year.

It is the general opinion of the profession that further debates or articles should be fairly measured against all sources of pollution and not unfairly target wood burners alone. The minutiae of the fixes for wood burning stoves are simple and the industry has made great progress in these areas already.

Surely, the issue of particulate emissions rests firmly in the hands of other industries; which now need to be ethical as we have always been, engage in debate and effect change.

For example; one wonders what is being done to educate the consumer with regards to, BBQ s Chimeneas, patio heaters and pizza ovens? Thousands of these are sold each year in the UK and yet such heavy polluters never make fair target for the press? As previously mentioned they are often used in the summer when pollution is at its highest. Also consideration too, should be given to bonfires and the burning of urban dung fires which produce extreme amounts of pollution.

In conclusion, the discussion on clean wood burning needs to be addressed holistically and not simplistically target any one tiny segment of the overall market.


Using a stove thermometer to ensure optimum efficiency

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Your newly acquired wood/multifuel stove will give months of long, easy & warm cosy days where you can lounge around just enjoying yourself. However, as with all things that are subject to temperature & pH variations, maintenance checks are essential.
Using a thermometer gives you peace of mind over safety and the satisfaction that everything is running under optimum conditions.

Often times these, “checks” may seem as if they might drag you out of your comfort zone but the good news is, that once you’ve attached it to the stove top (or flue pipe arising from it) using a thermometer is as simple as making regular readings. They come in a few varieties and can be wire, hose clipped or magnetically attached.

 

stove thermometer

Figure:1 Typical stove thermometer with “optimum operation zone”


Used primarily to avoid over firing, (the resulting extreme temperatures create bad fuel efficiency) and are operated by having an eye gauge in both °Celsius and Fahrenheit. Keeping your stove burning in the Correct range: 115°C – 245°C or  (240°F – 475°F) will ensure the safest operation, whilst simultaneously giving maximum fuel economy.

Running Too Cool

Allowing your stove to reach burning temperatures below 115°C or (240°F) will lead to incomplete combustion creating carbon monoxide, tar, soot and creosote.

Creosote itself, is a condensation residue of coal and/or wood particles, hydrocarbons, gases and other airborne debris. It is formed as gases cool, for example when air in a chimney is not hot enough to push the particles out. Its appearance is of a thick hard black shiny goo which is flammable and reduces the bore of the flue by sticking to it.

Running Too Hot

When you allow your stove apparatus to run above burning temperatures of 245°C or (475°F) you risk damaging your flue/liner/cowl and possibly warping your baffle plate.  The risk of chimney fires is significantly increased now, especially if there has been creosote build up.

Further Info

Choosing to read our other articles under ‘stoves’ or burning ‘wood’ to gain the knowledge needed to use your appliances to maximum efficiency under safe conditions is advisable. Please always remember a significant part of this maintenance strategy is to get your solid fuel heating appliances in use, swept at least once a year by your chimney sweep.

You can buy thermometers and wood moisture meters Here
NB/ We are in no way affiliated with this company and the link is only just to show an example of what items you may want

Multi Fuel or Wood Burning stove.. What’s the difference?

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Traditionally, stoves were intended to burn wood and only wood, then multi-fuel stoves were created to give you the option of heating your home with either coal or wood.      So , ..    Multi Fuel or Wood Burning stove ?
First off, you should know that it is NOT advisable to burn both coal and wood in your stove at the same time as this can and will damage your flue lining and stove itself. 

Why is it not wise to mix fuels 

Why can’t you mix fuels ? because corrosive materials such as halogens and sulphur found in coal will combine with the moisture in wood creating nasty, Sulphurous acid & other solutions that stick to and then erodes your whole stove system.
Whilst multi-fuel stoves bring with them the versatility of being able to choose which fuel you’d rather use at a particular time , their one limitation is the use of  ONLY One fuel at a time! Mixing fuels is not cool ! 

Only coal as fuel? ..Simple use Smokeless

You should always check your owner’s manual for the final word from the manufacturer on what fuels are recommended for use. Although most multi-fuel stoves are equipped to burn normal house coal, (aka bituminous coal) often most stove manufacturers will advise against this because of the high amount of soot in house coal.
**High soot content results in your stove system becoming rapidly clogged up**.
Using smokeless coal avoids this problem by agglomerating particles and reducing the amount of smoke and soot going up your flue , is also better for the environment and thus suitable for use in smoke control areas.

Knowing which stove is which , just by what you can see 

Multi Fuel or Wood Burning stove , the most obvious examples you can see immediately by eye are the:

1. External primary PRC & SRC secondary air flow regulator controls and 
2. Internal raised grate of multi fuel burners or the flat bottom non grate of wood burners.

Coal burns best on a ‘raised grate’ since it needs an air supply from below. Therefore , the primary airflow intake is below and its manually adjustable Primary Regulator Control outside (usually, somewhere near the bottom of the stove door & is normally either a sliding slat or turning knob/disc) is used to burn it effectively.

multi fuel burner showing SRC & PRC annotated in green Multi Fuel or Wood Burning stove

1. The PRC [below discs]  &  SRC [above slats] Regulatory Controls of a multi-burner

Wood doesn’t need this additional air supply below therefore , wood burners come with only a ‘flat bottom‘ . This limits the air supply to the fuel, resulting in a slower burn and you will see they ONLY have a top secondary air flow intake with manually adjustable Secondary Regulator Control. 

****        The adjustable multifuel grate in the picture below shows it can be both raised (top) allowing upwards air flow or it can be flattened (bottom) stopping upwards air flow from below.    ****

multi fuel adjustable grate Multi Fuel or Wood Burning stove

2. Multifuel adjustable Stove Grate

You will find that wood burns faster on a multifuel stove than on a normal wood-burning stove because of the extra oxygen and air flow from below. 

side view of multifuel stove showing air intakes Multi Fuel or Wood Burning stove

3. Primary, Secondary & Tertiary air intakes .. stove door to Left of pic

So what do I want to buy then?

In short , what to buy depends on what you are going to burn? If you’re thinking of using wood as your main fuel then it’s best to buy a wood-burning stove. By buying a multi-fuel stove, you are already almost committed to coal being your main fuel (but keeping the option open to burn wood if need be, albeit at a lower efficiency) and wood as an option.

Therefore , for the reasons already mentioned above , smokeless coal is your prime candidate fuel for a multi fuel stove. So you will be considering Anthracite, as well as a host of brand name alternatives such as Taybrite and Phurnacite. 
However , as you will see in our article on stainless steel liners there are some drawbacks to using these smokeless fuels. 

 Things to keep in mind::

1. Normal house coal is cheaper but too dirty for stoves 
2. Smokeless is expensive and more corrosive but burns clean enough & is better to use in stoves than bituminous
3. Unless you have a free source of weathered hard woods then having a multifuel means using smokeless coal IS the option. 
4. Don’t ever use wood and coal together at same time, water in wood dissolves sulphur in coal creating sulphurous acid !! ALL coal has sulphur , some worse than others.
5. Best to have a china hat/cowl to deflect water ingress. All lum/flue dampness causes sulphurous acid corrosion, esp with smokeless fuel
6. Smaller (within stove capacity) hotter hardwood fires are cleaner and don’t ruin baffle-plates or warp stoves
7. Read about liners on this site, 316 SS for wood and 906 for Anthracites NB/ sulphur ~ halogen corrosives
8. In olden days damper plates were used to control burning[often slumbering Tutt Tutt!!] by choking the fumes exhaust rather than the air intake itself reducing combustion. This is dangerous due to the accumulation of toxins rather than reducing their creation in combustion control itself. 

Using a wood [you see SRC only ! Flat Grate] only stove:-
You would be controlling the flames ONLY by the Secondary air flow intake [see picture 1 above] by manually adjusting the Secondary Regulator Control. Correct settings would be seen as curling yellow flames emanating from the mixture of gases combusting above the fuel on the grate.

Using a multi [you see PRC & SRC Raised Grate] fuel stove:-
You would control the main flames by using the Primary Regulator Control [see picture 1 above] then adjust further also with more tighter control to satisfactory conditions by the SRC [see picture 1 above]. Visually blue/orange flames would be seen below and yellow ones above the fuel.