Checklist

If you're about to buy a woodburner, here's what to consider.

Type

Freestanding models are generally the most efficient (for a given firewood load, they return the most heat to a room). They're also the cheapest to install. But if you have an existing open fireplace, an insert model is most often the way to go. Although insert models are not as efficient as freestanders, they're way better than an open fire.

Heat output

Choose a woodburner with a heat output suitable for your home. If you have a non-draughty well-insulated home in the north of the North Island then 10kW should be plenty. A larger house – or the same-sized but less-well-insulated and draughty house – further south will require more heat output. Think in terms of 12-14kW.

In non-open-plan houses there's no point in overheating the lounge while the rest of the house stays cold. Install a heat-distribution system to help spread the heat throughout the house.

Be careful about manufacturers' heat-output claims – some grossly exaggerate what you'll get. Always check the compliance plate (pictured). This has to be on every woodburner that's sold – and it states the tested heat output, along with the efficiency and emissions rate. See Heat output for more information.

Convector vs radiant

All woodburners both heat the air and radiate heat on to objects that are within a few metres of them. But some woodburners are marketed as predominantly one type or the other. It depends on the external design of the firebox.

• A convector heater heats the air immediately around it. Hot air is lighter (less dense) – so it rises away from the heater and gets replaced with cooler air that’s in turn heated. This convection air-current means that the warmest air in the room ends up near the ceiling with the coolest air near the floor. Convector heaters are air warmers.
• A radiant heater “shines” heat on to anything in its path. That could be you if you’re near the fire, or furniture within a few metres of the fire.

Tip: Convectors are best for well-insulated non-draughty houses with low ceilings. Radiant-type models suit older and less-well insulated (or draughty) houses with higher ceilings.

Controls/cleaning

The controls should operate smoothly, and it should be relatively easy to clean the outer surfaces and empty the firebox.

Flue system

The flue must have a larger diameter outer shield around it where it passes through the ceiling and attic space. Some of the newer designs have this air-gap vented outside rather than into the room (outside venting stops hot air escaping from the room). Some other woodburners get the air needed to burn the wood from outside the house rather than from within the room: this improves efficiency and reduces drafts.

Emissions

The lower the particulate emissions from your fire, the less of a health hazard you'll be causing. You can find this out from the woodburner's compliance plate. See Emissions and efficiency for more information about emissions.

Wetbacks

A wetback uses copper pipes to circulate water from the woodburner to the hot-water cylinder and back. They're expensive to install and the hot water cylinder needs to be placed reasonably close to the burner. The payback period for a wetback depends on how you use your woodburner: if the woodburner's not used every day, a wetback is unlikely to be cost effective. See our section on wetbacks for more information about this type of woodburner.

Safety guards

Woodburner surfaces can get very hot and can be a danger to small children. Protective guards are available, and highly recommended.

Building consent

Before you buy a woodburner, make sure your local authority will allow you to install the model you want: some councils will only allow installation of models from their recommended list. You will also need to get a building consent before you install your woodburner (you're unlikely to get one retrospectively). If an illegally installed wood-burner causes a fire, it may invalidate your insurance cover.

Installation

A poor installation job can ruin the heating and emissions performance of the best of woodburners. Check that your installer has New Zealand Home Heating Association certification or is otherwise suitably experienced.