Solid fuel burner – deterioration of metal firebox

Solid fuel burner/woodburner (closed firebox) – deterioration of metal firebox

Causes

Firebox is at the end of its serviceable life

Cause

Firebox is at the end of its serviceable life

Repair

  • replace the unit. Installing, replacing or moving a woodburner requires a building consent from your local building consent authority (a city or district council in most cases). The BCA will typically want to know where the woodburner is to be installed in the house, roof type, proposed flashings, flue and woodburner clearances and seismic restraints, and the exact make and model of the heater

  • contact an experienced installer. You can find a list on the website of the New Zealand Home Heating Association

  • identify what types of woodburner are permitted in your location. For a start, the National Environmental Standards for Air Quality require that all wood burners installed on properties less than 2 hectares must have:

    • a discharge of less than 1.5 grams of particulate for each kilogram of dry wood burnt

    • a thermal efficiency of at least 65%.

    • you can find a list of appliances that comply with these requirements at the Ministry for the Environment website

  • stricter rules apply in some locations such as parts of the Bay of Plenty, Hawke’s Bay, Nelson, Canterbury and Central Otago. Higher environmental requirements mean that only ultra-low emission burners can be installed. These burners must meet an emissions and efficiency standard of 38 milligrams per megajoule or emit less than 0.5 grams of particulate for each kilogram of fuel burned and have a thermal efficiency of at least 65%

  • houses on sections larger than 2 hectares have much more freedom of choice. This includes woodburners that emit higher levels of emissions but continue burning overnight

  • you can find more details in the BRANZ bulletin BU654 Installation and maintenance of solid fuel appliances