How Often to Service a Gas Heater in Adelaide, and What a Real Service Includes

Service a gas heater every 2 years as a baseline, and every year if it is open flued, over 15 years old, or running most of the day through winter. That interval comes from the manufacturer instructions and from AS 4575, the Australian Standard covering servicing of Type A gas appliances. A real service means a carbon monoxide spillage test, a gas pressure test, burner and heat exchanger inspection and a flue check. A vacuum and a wipe down is a clean, not a service.

Need this sorted rather than explained? Gas Fitting in Adelaide. Also worth reading: The 5 Silent Signs of a Gas Leak in Your Home, and What to Do First · Why Is My Kitchen Sink Gurgling When I Flush the Toilet?

How often, by appliance type

The interval is not a plumber's preference. It comes from the manufacturer instructions supplied with the appliance, and from AS 4575, the Australian Standard for servicing Type A gas appliances. Almost every domestic heater sold here carries a 2 year interval in its manual, and a shorter one applies once risk factors stack up.

Appliance	Interval	Why that interval
Flued gas space heater	Every 2 years	Combustion is separated from the room, but flue, seals and burner still degrade
Open-flued space heater or wall furnace	Every year	The highest carbon monoxide risk in the house, and directly affected by room air pressure
Ducted gas central heating	Every 2 years, yearly past 15 years	Heat exchanger cracking and duct leakage, neither visible from a floor vent
Unflued portable or wall-mounted heater	Every year	Combustion products vent into the room, so the burn must be clean
Gas log fire or decorative flame effect	Every 2 years	Low output, identical flue and combustion checks
Outdoor patio heater on a cylinder	Hose and regulator each season	A perished hose and a failing regulator are the common faults, not the burner

Recommended service intervals for domestic gas heating

Move to annual servicing if the appliance is open flued, more than 15 years old, runs more than roughly 8 hours a day in winter, or heats a house with an infant, an elderly resident or someone with a respiratory condition. Rentals are their own case: the landlord carries the safety obligation and needs paperwork proving it was met.

Why Adelaide heaters fail on the first cold night

Adelaide has a short, sharp heating season, and it does more damage to gas appliances than a long one would. A heater in a plains suburb sits untouched from roughly October to May. That is 7 months doing nothing in a dusty cavity, sub-floor or outdoor housing, which is the condition that produces a failure on the night it is finally needed.

Dust and lint settle across the return air path. A choked return is the most common cause of a unit lighting and then shutting down on its overheat cut-out.
Spiders build in pilot assemblies and injectors over summer. A single web in an injector orifice will stop a pilot holding, and it is among the most common faults on an idle appliance.
Wasps, birds and leaf litter block flue terminals. A partly blocked flue does not stop the appliance working, it stops the exhaust leaving, which is the dangerous version.
Rodents chew duct and wiring in underfloor ducted systems, so the first run of the season heats the sub-floor rather than the house.
Thermostats drift. A control reading 3 or 4 degrees out will either short-cycle the burner or run it constantly, and both shorten the life of the appliance.

Location changes the load. The Hills sit several degrees colder than the plains and heat for longer, so a unit in Stirling, Aldgate or Bridgewater accumulates far more running hours per winter than the same unit in Cumberland Park. Many Hills properties are also on bottled LPG, which runs at a different pressure through different injectors. An appliance converted between the 2 fuels without the correct injector change burns badly, and burning badly is how carbon monoxide is produced.

The inner-south housing stock adds its own load. A wall furnace in a 1920s bungalow in Goodwood or Colonel Light Gardens holds temperature in a room with 3 metre ceilings, single glazing and very little insulation. The same appliance in a modern build cycles off and rests. The one in the bungalow runs, which is why the older suburbs surface end-of-life heaters first.

What a real service includes

Visual inspection of the appliance, its clearances and the room around it, including anything built, shelved or curtained too close since last time.
Gas supply pressure measured at the appliance test point, and a soundness test on the installation in line with AS/NZS 5601.1.
Burner removal, cleaning and inspection. Injectors cleared, pilot assembly and thermocouple cleaned, flame pattern checked.
Heat exchanger inspection for cracks, corrosion and scaling. This component separates combustion products from the air in the room, and its condition decides whether the appliance stays in service.
Flue and terminal inspection: obstruction, corrosion, dislodged sections, nesting, and correct clearances from windows and eaves.
Carbon monoxide spillage test with a calibrated analyser, run with the room at its worst: doors and windows shut, and every exhaust fan, rangehood and ducted vacuum running.
Thermostat and control calibration, fan operation, and a function test on the safety interlocks and overheat cut-out.
A written report listing what was tested, the actual readings, and any component needing replacement.

The step people underestimate is the spillage test, and specifically the conditions it is run under. Performed with the back door open it tells you nothing, because that is not how a house is run on a cold July night.

Open-flued heaters and the exhaust fan problem

An open-flued heater takes its combustion air from the room and vents its exhaust up a flue relying on natural draught, which is weak. Anything that lowers the air pressure in that room can overcome it and pull combustion products back down the flue into the living space. That is spillage, and it is the mechanism behind the carbon monoxide incidents that make the news every winter.

What causes it is ordinary domestic behaviour: a rangehood on high, a bathroom exhaust fan, a ducted vacuum, a dryer venting indoors, and modern draught sealing that leaves no replacement air path. A house that was safe with an open-flued heater in 1998 can be unsafe after a kitchen renovation added a high-extraction rangehood.

Soot marks or discolouration on the wall above the heater.
A stuffy or acrid feel to the room that lifts within an hour of the heater going off.
Heavy condensation on the windows while the heater runs.
Headaches, nausea or drowsiness across the household that improve at work and at school.
A pilot or flame that visibly lifts when the rangehood is switched on.

The blunt advice: if the unit is old, if the room has been sealed up or a rangehood added since it went in, and if it fails a spillage test, decommission it rather than patch it again. Specific open-flued heater models have been the subject of Australian product safety warnings and recalls on exactly this hazard. A carbon monoxide alarm buys warning time, but it does not make an unsafe heater safe.

When a heater is not worth servicing

Servicing keeps a sound appliance sound. It does not rescue one that has reached the end, and servicing a unit that should be replaced is money spent delaying a decision.

A cracked or corroded heat exchanger. Not repairable on a domestic appliance. The unit is condemned, disconnected and tagged.
A unit that fails a spillage test and cannot pass without rebuilding the ventilation of the room around it.
Parts no longer available. Many wall furnaces and ducted units from the 1990s have no supported burner, fan motor or gas valve left in the country.
Past 20 years on a ducted system or wall furnace. Efficiency is a fraction of a current unit, and the next fault is close behind the one you just paid to fix.
A repair quote reaching half the installed cost of a replacement. Past that point, replacing buys a warranty and 15 or more years, and repairing buys a season.

Where the decision usually lands: a serviceable 8 year old flued heater with a failed igniter is a repair, and an easy one. A 22 year old wall furnace with a discoloured heat exchanger, a pilot that will not hold and no parts support is a replacement, and paying to keep it limping season after season is the more expensive path over 5 years.

A growing share of Adelaide households replacing a dead gas heater move to reverse cycle instead. A reverse cycle unit moves several units of heat for each unit of electricity it uses, and a gas heater can never exceed the energy in the gas it burns. Whether that stacks up depends on the tariff, solar on the roof, and how many rooms need heat.

Booking, and what you can safely do yourself

Book between February and April. The Adelaide pattern repeats every year: the first cold front arrives, thousands of heaters get switched on for the first time since spring, and a share of them fail that night. Every gas fitter in the city is then booked a fortnight out. A service in late summer costs the same and comes with a choice of dates.

Vacuum the return air grille and the front grille. A choked return air path is the most common cause of an overheat shutdown, and this is the one item here that prevents a callout.
Move furniture, curtains, drying washing and stored boxes back to the clearances printed on the data plate.
Look at the flue terminal outside for a bird or wasp nest, and clear leaf litter away from a ducted unit under the floor.
Clean or replace ducted system filters if the manufacturer states they are user serviceable.
Fit a carbon monoxide alarm in the room with the heater and outside the bedrooms, and test it each season.

Marc is a licensed plumber and gas fitter with 20 years behind him, and he attends the jobs himself. You get a text with an arrival time before he sets off, and the price is discussed up front. If the heater is past saving, you get told on the day.

Questions we get asked

How often should a gas heater be serviced in Australia?

Every 2 years for most domestic gas heaters, which is the interval printed in the majority of manufacturer manuals and supported by AS 4575, the Australian Standard covering servicing of Type A gas appliances. Move to every year if the appliance is open flued, more than 15 years old, running most of the day through winter, or heating a house with an infant, an elderly resident or someone with a respiratory condition.

Can I service my own gas heater?

No. You can vacuum grilles, clear clutter back to the marked clearances, check the flue terminal outside for nests, and replace user serviceable filters on a ducted system. Everything else is licensed gas fitting work in South Australia: removing a burner, touching an injector, adjusting pressure, opening the gas valve, altering a flue, or converting between natural gas and LPG. An unlicensed repair voids the appliance warranty and most home insurance policies.

What are the signs my gas heater needs servicing now?

Yellow, orange or floppy flames instead of crisp blue ones. Soot marks around the burner or on the wall above the unit. A pilot that will not stay lit. A burner that lights with a delayed thump. Uneven heating across a ducted system. New rattles or grinding from the fan. Heavy window condensation while the heater runs. Any of those means book before the next cold snap. If there is a rotten egg smell too, treat it as a gas leak and evacuate first.

Do I still need a carbon monoxide alarm if the heater is serviced?

Yes. A service confirms the appliance was safe on the day it was tested. An alarm watches it for the 2 years in between, and catches what a service cannot predict, such as a bird nesting in the flue terminal in March or a new rangehood changing the air pressure in the room. Fit one in the room with the heater and one in the hallway outside the bedrooms, and test it each winter.

Is it worth servicing a 20 year old gas heater?

Often not, and this is worth being straight about. Past 20 years the efficiency is a fraction of a current unit, parts support for many models has ended, and a heat exchanger of that age is the component most likely to condemn the appliance during the inspection. Booking the service is still the right first step, because it establishes whether the unit is safe to run at all. What it should not become is an annual payment deferring a replacement decision already made for you.