Wood burners

Modern wood burners are highly energy efficient, produce limited air pollution and use a form of renewable energy - so are essentially carbon neutral.

Benefits of modern wood burners

  • They’re relatively cheap to run - even if you have to buy firewood.
  • Wood is renewable and sustainable - and New Zealand has extensive areas of forestry.
  • Burning wood from sustainable forests is carbon neutral - while trees are growing, they capture carbon dioxide from the air. This carbon dioxide is released either when the wood is burnt, or when the tree dies and rots. While some emissions are produced in the transporting and processing of the wood, this is only a very small amount per unit of heat produced.
  • Wood burners work during power cuts – many free-standing models can be used for cooking as well as heating.
  • Some wood burners can be equipped with a wetback system to heat water - check with your supplier about this option.

Wood burner checklist

  • Insulate first - starting with your ceiling and floor. This will make your house easier and cheaper to heat properly.
  • Get a building consent - from your local city or district council to install a solid fuel burner. Check with them to find out if they have any extra requirements for solid fuel burners.
  • Choose an authorised wood burner - burners installed on properties less than 2 hectares in size must meet certain emissions and efficiency standards. Check out the Ministry for the Environment's list of authorised wood burners via the link below.
  • Work out what size you need - wood burners need to be carefully matched to the room or rooms you want to heat. Ask your heating supplier to advise you on the right size heater for your needs.
  • Buy a heat transfer kit - most wood burners generate more heat than you need for one room. Unless your house is open-plan or has internal door openings that go right up to the ceiling, excess heat won’t easily get to other rooms. Heat transfer kits distribute the heat by pumping the warm air into other rooms in your house. You can buy these kits from DIY stores, but we recommend you contact a professional tradesperson for advice as there are a lot of factors that can affect how well they work.
  • Decide whether you want more radiant or convective heat - wood burners release their heat through a combination of heat radiation (which heats objects) and convection (which heats air). The amount of each varies from model to model.
    • Radiant heat - wood burners that produce mostly radiant heat make the room feel warmer than the air actually is. This makes them particularly suitable for large rooms with high ceilings and for rooms where you have poor insulation and draught issues.
    • Convective heat - convective wood burners heat the air around them, which then rises to the ceiling. This means you get less heat in the bottom part of your room, unless you use a ceiling fan to mix up the hotter and cooler layers of air. Convective heat makes it easier to move some of the warm air to other parts of your home.
  • Use a certified installer - quality installation is fundamental to your wood burner's performance and safety. We recommend that you have your wood burner installed by a Solid Fuel Appliance Installation Technician certified by the New Zealand Home Heating Association.

Local council website directory - LGNZ website

List of authorised wood burners - Ministry for the Environment website

New Zealand Home Heating Association website

Using wood burners wisely

  • Follow the manufacturer's operation and safety instructions.
  • Use safety guards to protect children and pets.
  • Plan ahead and use well-seasoned, dry firewood - it should be stored under cover in a well-ventilated, windy and sunny place for at least a year to dry out before use.
  • Use the right wood at the right time - lighter wood (often called 'softwood') like pine is good for making kindling and getting a fire started. Once you have a good bed of coals burning, denser wood (hardwood) will burn for longer and give more heat. If you can, use wood from plantation forests (for example pine and gum) rather than native woods like manuka.
  • Don’t use chemically treated wood or salt impregnated wood like driftwood -they can corrode your wood burner and flue, and may emit toxic gases and leave toxic residues in the ash and flue.
  • Don’t burn coal in a wood burner, unless the manufacturer specifically says you can - otherwise you can damage your wood burner.
  • Regulate the heat output by adjusting the amount of fuel you load - don’t dampen the air control.
  • Keep the air setting high enough for a clean burn - too much or too little air cools the fire, and produces smoke. Place large pieces of wood on a good bed of glowing coals and set the burner at a high temperature.

Maintaining your wood burner

Whether you have a new or old wood burner, maintaining it regularly is important for safety, performance and longevity. Most wood burners and flue systems have parts that you need to replace or clean periodically. Don’t burn coal in a wood burner or you’ll damage it. Ask the manufacturer to recommend someone to inspect and service your wood burner, or contact the New Zealand Home Heating Association for advice.

New Zealand Home Heating Association website

Open fires and older wood burners

Open fires are often inefficient - most of the heat is lost up the chimney. They can warm the room they occupy, but they create a draught that draws cold air flows into the rest of the house. They also produce large amounts of air pollution. Older wood burners and pot belly stoves are also inefficient and produce air pollution.

What to do with old open fires

If you have an open fire that you don't use, block up the chimney with some old newspapers to stop draughts. If you do block the chimney, make it impossible for someone to light a fire in the grate. Enclosed solid fuel burners can often be fitted into an open fire space and perform much better.