If you smell gas
Inside, WorkSafe's steps are: keep flames and cigarettes away, and don't flick any electrical switch on or off, because the spark could ignite the gas. Don't use your mobile phone in the area. Turn off the valves to your gas appliances if you can do it safely, turn off the gas supply at the meter or LPG cylinder, and open doors and windows. If the smell persists, go outside to a safe place away from the building. Outside, keep flames, cigarettes, vehicles and electrical equipment (mobile phones included) away, turn off the gas at the meter or LPG cylinder, and leave the area. Dial 111 in an emergency. For a gas supply problem, contact your gas retailer (the company that sends your gas bills); for a problem with a heater or other appliance, contact a licensed gas worker.
Unflued gas heaters put their fumes in the room
EHINZ says portable, unflued gas heaters release water vapour, nitrogen dioxide, carbon monoxide and other pollutants indoors. For health and safety reasons, BRANZ doesn't recommend any sort of unflued gas heater, natural gas or LPG. They add moisture to a house that may be damp already, and they can never count towards a rental's heating standard. If one is your main heater, replacing it belongs near the top of the list.
Flued heaters, gas fires and cabinet heaters
A flued gas heater is fixed to the house and sends its combustion fumes outside through a flue. BRANZ notes that gas combustion byproducts include carbon monoxide and nitrogen dioxide, which must be vented outside, and the flue is what does that. It's why a gas heating specialist will look at where a flue can go before recommending a model.
A gas fire, the flame-effect kind set into a wall or an old fireplace, is a gas heater too, and should be flued for the same reason. Unflued heaters, such as portable LPG cabinet heaters, burn gas inside the room. EHINZ found unflued portable gas heaters were a main type of heating in 2.5% of dwellings nationally in 2023.
Natural gas or LPG?
Natural gas comes through pipes, called reticulation, and only in parts of the North Island. Te Waihanga says the South Island has none, and that bottled LPG is an important fuel there. So in Christchurch, Dunedin, Queenstown or Invercargill, a gas heater means LPG bottles.
North Island networks belong to different companies: Vector in Auckland, Powerco in Hawke's Bay, Taranaki, Manawatū and the Wellington metropolitan area, Firstgas in parts of Northland, Waikato, Bay of Plenty and Gisborne, and GasNet in Whanganui. A network in your suburb doesn't mean your house is connected, so check with a gas retailer before you pick a natural gas heater.
Gas heater or heat pump?
BRANZ sorts heating by efficiency. Flued natural gas and LPG heaters sit with wood and pellet burners in its 'average efficiency' group, with a coefficient of performance (COP) below 1. Heat pumps are in its best group, and BRANZ says a heat pump gives the same heating from much lower energy input than a standard gas heater.
So if running efficiency matters most, the heat pump wins on BRANZ's figures. If a real flame matters more, a flued gas fire gives you one. Our heating comparison sets the options side by side.
Who can legally do which part?
Installing, altering or repairing a gas appliance, including its gas pipes, flue and commissioning, is gasfitting work, and the PGDB says homeowners can't do it. You can work on portable appliances with the gas bottle attached, like barbecues and patio heaters, though the PGDB strongly recommends a gasfitter even then.
The PGDB registers and licenses gasfitters, with the Certifying Gasfitter as its highest class. Its public register, searchable by name, town or company, shows a gasfitter's licence history, any conditions, and whether they've been disciplined in the last three years.
Christchurch City Council says permanently fixed gas heaters don't need a building consent there, but must be installed or supervised by a certifying gasfitter who certifies their own work. If the heater needs new fixed wiring for a fan or ignition, that part is for a registered electrician.
The paperwork you should end up with
A gasfitting certificate
Either a Gasfitting Certificate of Compliance or a Gas Safety Certificate. The PGDB says these are legal documents under the Gas (Safety and Measurement) Regulations 2010, and the Building Act 2004 recognises them as an Energy Works Certificate.
On time
The gasfitter must give it to you within 20 working days of connecting the work to the gas supply, and keep their own copy for seven years.
Somewhere you'll find it
Gas providers may ask to see it before they supply gas or refill your LPG bottles, so keep it with the heater's manual.
What a good gas heater quote covers
- The heater model, its output in kW, and the room it's meant to heat.
- The flue route, and where it comes out on the outside of the house.
- Natural gas or LPG, and for LPG, where the bottles will sit.
- The gasfitter's name and PGDB registration.
- The gasfitting certificate, and a CoC if there's any new wiring.
- Removing any old heater and making its gas point safe.
Your job, and the gasfitter's
You can
- Keep the space around the heater and the outside flue outlet clear, as the manual says.
- Clean the outside of the heater and any filter the manual says you can reach.
- If a heater isn't working the way it used to, stop using it and get a gasfitter to look.
- Keep the gasfitting certificate with the manual.
Leave to a licensed installer
- Installing, moving, altering or repairing a gas heater.
- Gas pipes, the flue, and commissioning.
- Any new fixed wiring for the heater.
- Taking out an old heater and capping its gas supply.
What we'd do
If it were our home
We'd retire any unflued heater first, whatever else we did. Then we'd compare a flued gas heater with a heat pump for the same room. On BRANZ's efficiency figures the heat pump comes out ahead, and in the South Island the gas option means LPG bottles. If a real flame is what you love, a flued gas fire put in by a certifying gasfitter is a fair choice, as long as the certificate turns up on time.