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Why is my Pyroclassic using more wood than I thought it would?
This could be because the loading door is not airtight. Check the gasket - if you need a replacement, you can purchase one from our Parts Shop.
Another common cause of this is incorrect operation. Remember the Pyroclassic IV's significant heat storage capacity. Add logs less often and burn fuel further back in the fire chamber.
Lastly, this can happen if the Turboslide is being left open for long periods. If this is the case, go to our Resources Page and download our operating instructions and read about how to use it correctly.
My flue pipe has gone a copper colour in one section. What has happened?
If there is a concentrated spot of heat like a ring around the pipe then this is an indication of a possible internal flue fire. This is caused by a build up of creosote within the flue pipe which has then caught fire. If this is the case then a sweep would be recommended. Make sure you are using a sweep that has done a Pyroclassic fire before or has watched our video about flue cleaning. It would also pay to check the moisture content in your wood by splitting one of your logs in half and spiking it with the moisture meter that came with your Pyroclassic IV. Wood should be less than 20% to burn clean & efficiently.
Where does the wood burner standard apply?
Everywhere in New Zealand on properties of less than two hectares.
Our Pyroclassic fire appears to have 'rust-like' dust coming out at the bottom. What is this?
The rust dust is probably just the exposed bottom edges of the top valley walls where they meet the cylinder rap rusting a little bit due to moisture passing through the fire from the wood fuel. This is where it tends to collect and is quite normal to see and is nothing to be concerned about.
The front of my Pyroclassic fire has developed smoke stains on the panel. What can I do?
Depending on how extensive the marking is you may be able to remove it by using a light abrasive car polish. Remove the panel and place it on a kitchen bench as this will be much easier than doing it on the fire. Please be careful of the gasket if it's still attached to the back of the front panel when removing and replacing it. Please avoid handling the panel when hot. Always make sure the panel is cold.
What wood should I be using?
DRY. This means a maximum of 25% moisture content but ideally under 18% if possible.
Do not burn any wood which has been treated as this will release poisonous gases and dioxins. Do not use any driftwood as the salt content can cause irreparable damage to the ceramic cylinder and metal components. Younger softwoods and timber which has a higher moisture content will produce a greater volume of creosote and soot than dry, well seasoned hardwood.
Logs should be approximately 100mm - 120mm in diameter by around 300mm - 400mm long for your Pyroclassic IV Fire. Logs should be approximately 100-120 mm in diameter by around 200-250mm long for your Pyroclassic Mini Fire.
Dry wood is a must. To get the heat out of wood the fuel must pass through several stages. Firstly, free water that is not chemically bound with the wood is driven off – even wood at 20% moisture content still has to get rid of 2 litres of water for every 10 kilograms of wood. In the second stage the wood breaks down into the volatile gases, liquids and charcoal. Finally, the charcoal is also gasified, burning with a very short flame close to the char surface that appears to glow. In wood stoves all stages proceed simultaneously.
Wood is the most prolific worldwide, solar embedded, carbon sequestered energy source which is renewable in a human lifetime. It will provide energy when the sun is not shining and the wind is not blowing, when the outside temperature is above or way below freezing and when the electricity is not coming out of that little hole in the wall. If the abundant, worldwide timber resource is managed correctly it is the most sustainable, environmentally safe, renewable, resource we have and it has sustained mankind for centuries, providing us with warmth for the space we live in, warm water to clean with and the ability to cook food.
With the discovery of more energy intensive and easily transportable fossil fuels, wood was relegated to a lowly place in the order of preference and although it is bulky to transport it is the safest as it does not need a specially built pipeline, it won't suddenly explode or cause devastating marine pollution and with almost no refining can be used in its raw state. The closer it is used to the place where it has grown makes this an even more environmentally friendly product.
Most designer wood burners catering to aesthetic demands totally disregard the thermal conductivity of wood. Microscopic examination of wood shows the channels which carry the liquid nutrients up and down the tree; consequently the properties of wood are very different along the grain than across it. Heat moves along the grain about fifteen times faster than across it, therefore, solid wood across the grain does not conduct heat and is an effective insulator meaning it does not readily burn.
When a fire is lit, even by rubbing two sticks together, the gasification process starts and it is the combustion of these gases with air that produce heat which we see as flames and smoke. When heat cannot penetrate wood easily, i.e. across the grain, the volatiles given off are not rich enough nor hot enough to burn efficiently. Efficiency apparently is not a consideration in such panoramic appliances.
This is getting to the really nerdy bit now...
Burning of the volatile gases delivers over 60% of the heat stored in the original log but few heaters can recover the major portion of this heat as the volatiles must be over 600°C and mixed with hot oxygen to burn them. Now these are difficult conditions to meet and here’s why: if the main air supply comes from under or around the burning logs, the glowing char consumes all of the oxygen - it takes only 5cms of glowing char to consume all the available oxygen. At that point, incomplete combustion continues as characterised by increased carbon monoxide and tars which mostly go up the chimney where the unburnt volatiles deposit on the flue walls as a highly flammable, gummy substance known as creosote. It is wrong to introduce cold secondary air above the fuel as it cools the gases below their ignition temperature and now they won’t burn at all. The requirement is to introduce a highly pre-heated but variable volume of air for the different stages of combustion. This is done very efficiently by the secondary air tubes inside the Pyroclassic IV fire.
All fires consume large volumes of air in order to extract the oxygen required to burn their fuel. One kilogram of wood needs 3.7m3 of air to burn completely, although this is only a theoretical minimum for stoichiometric combustion. Such ideal combustion does not exist in real life as only some of the oxygen in that amount of air can be used and therefore 'cool fires' need some 200% - 300% excess air to get the oxygen they need. Therefore some 7 - 10m3 of air per kilogram of wood pass through the firebox cooling the core temperature inside it and cooling air below 600°C , which kills the reaction needed to burn the volatiles. In most fires the air needs of the fire make it work against itself making it inefficient and polluting, the excess air it uses only goes up the chimney with all that gas, tar and particulates. A Pyroclassic IV only uses super-heated air in its secondary burn cycle ensuring there is no cooling of the firebox and no excess air consumed.
Burning wood scientifically is done very effectively by the Pyroclassic IV freestanding woodburning fire but even the cleanest and most efficient woodburning stove needs logs which are as dry as possible to give the best output from your fuel. Check the moisture content of your wood when you buy it and then let nature do the hard work for you. Stack it off the ground in an open sided, roofed store to allow plenty of air flow around it for as long as possible or at least until the moisture content is below 20%. It’s then ready to be used in your Pyroclassic fire to give you a nice warm house right through winter in the most efficient and cleanest way possible.
How does the Pyroclassic IV burn overnight?
The overnight burn ability of the Pyroclassic IV is 100% dependent on the quality and size of fuel you put in it.
You will need to have a good ember bed established, then add 2 or 3 dry hardwood logs (preferably Kanuka) measuring approximately 400mm long by 120mm thick into the fire box. Allow the flames to establish on the front ends of the logs and then ensure the turboslide is fully closed meaning the air flow into the fire is controlled by the fire itself. The further back in the fire chamber you have the fire the longer it will burn for.
Remember, you need to add a kilo of fuel for every hour burn time required. If you follow these instructions you should have some hot embers left in the back of the fire chamber in the morning ready to be brought forward to establish another fire.
As a point of caution you should never insert a fresh log which is too large or placed in the fire too late to ensure a flaming combustion, doing this will cook the wood fuel on the remaining embers releasing unburnt volatile gases into the combustion chamber which will eventually reach a point of ignition, this can result in a sizable explosion inside the fire chamber and may cause damage to the unit.
When and how should I clean the flue?
Pyroclassic Fires are renowned for burning very cleanly when dry fuel is used but you should still always clean your flue once a year. This is often a requirement for many insurance companies.
Keeping your flue pipes clean will help eliminate the risk of a flue fire. Your flue is also a great indication of how your wood fuel is performing. If the pipes are clean then the wood is good, if the pipes are filling up with carbon, creosote and tar deposits then you may need to revisit the operating instructions and refresh yourself with how to create a cleaner burning fire.
The easiest way to clean the flue is by placing a deep baking tray or similar under the base of the flue and sweep the flue down into this, this stops all the debris from falling into the top chamber and requiring vacuuming out. Sweeping the flue into the top chamber is never a good idea as it can restrict the flow of gasses from the primary fire chamber and cause your fire to perform poorly.
To clean the top chamber and wetback, you will need to remove the top plate (it just lifts off) and clean out the top chamber of soot and creosote. Take care not to remove any of the Kaowool lining during cleaning and ensure that the gasket is all intact before replacing the top plate. Support the flue with a frame made of wood so you can easily remove the top plate.
The build-up around the wetback is best removed by hand. The wetback can be knocked out of alignment if it is moved when the creosote is being cleaned off so be careful as this can cause the constant rise to be knocked out of alignment and can result in water hammer developing in the system.
Refuelling onto a low firebed
The wood fuel inside a Pyroclassic® IV fire burns best on a thin bed of ash and hot coals. However, if there is insufficient burning material in the fire bed to light a new fuel charge, excessive smoke emission can occur. Refueling must be carried out onto a sufficient quantity of glowing embers and ash so that the new fuel charge will ignite in a reasonable period, add suitable kindling if necessary. If a new fuel load is left without suitable ignition then a buildup of unburnt volatile gases can occur, this can cause the unit to be put under stress when these gases eventually do combust causing a possible internal explosion. Always ensure adequate combustion and ignition of fuel and use the Turboslide as instructed.
Who should I use to install the fire?
As a responsible manufacturer we recommend that all our fires are installed by a New Zealand Home Heating Association approved installer. This will ensure the fire is installed correctly and safely and will provide many years of worry free comfort.