Pre-Winter Gas Heater Checklist: Prepare Your Heating

15 June 2026Blog8 min

Preparing your gas heater before winter can help identify issues early, support efficient operation where the appliance is in good working order, and reduce the chance of avoidable problems during the months you rely on heating most. This checklist is designed for any homeowner, whether you carry out annual upkeep on a familiar system or are looking after a gas heater for the first time.

It covers the visual inspections and basic maintenance tasks you can do yourself, how to test your heater before cold weather arrives, the signs that a professional service is needed, and when to call a licensed gasfitter. None of the steps below require technical knowledge or tools beyond what most households already have.

As your gas distributor, Australian Gas Networks is here to help you understand what to look out for and get the right support. If you ever smell gas at any point, stop what you are doing and go directly to our gas leaks and emergencies page for immediate guidance.

Dog resting in front of a gas heater at home

Key Summary

Start Early: Run your heater on a mild day in late summer or early autumn to catch problems before cold weather arrives.
DIY Checks: Many homeowners can carry out simple visual checks, filter checks, and a short test run, provided they follow the manufacturer’s instructions and do not open, adjust, or interfere with gas components.
Professional Service: A full gas heater service, including any work on gas supply connections, burners, flues, heat exchangers, internal components or safety controls, must be performed by an appropriately licensed gasfitter. Book before winter when availability is better.
Warning Signs: Unusual noises, persistent odours, or repeated ignition failures all warrant a call to a licensed gasfitter.
Gas Emergency: If you smell gas at any point, turn off the heater, ventilate the space, leave the property, and call 1800 427 532 immediately.

Why a pre-season gas heater check matters

Gas heaters that sit idle over summer can accumulate dust, develop minor faults, or lose efficiency without any obvious sign. A pre-season check can improve your heater run as intended and can help identify safety issues before they become serious. It also puts you in a better position practically: gasfitters are significantly more in demand once winter sets in, so if your heater does need attention, organising it in autumn is far easier than finding someone available mid-July.

What you can check yourself before winter

Several basic checks can be done by any homeowner without tools or technical knowledge. These checks help you spot obvious issues before booking a professional service. They do not replace a professional service, and none of them involve opening the heater or adjusting any internal components. If you are ever unsure whether something is within your scope, the safe choice is to contact a licensed gasfitter.

Visual inspection of external vents and flues

Walk around the outside of your home and locate the external vent outlets or flue for your gas heating system. These are typically grilles, louvres, or pipes mounted on an external wall or roof. Check that they are free from obvious blockages such as leaves, cobwebs, bird nests, debris, or objects that may have been placed in front of them over summer.

Blocked vents can prevent combustion gases from escaping properly, which is a safety concern. Clearing an accessible external vent of debris you can reach without tools or ladders is a reasonable task for a homeowner. If a vent appears damaged, corroded, or blocked in a way you cannot clear safely from the outside, contact a licensed gasfitter to inspect it before using the heater.

Checking and Replacing Filters

Ducted gas heating systems typically have a return air filter, usually located behind a grille on a wall or ceiling inside the home. This filter captures dust and particles before air enters the heating unit. A clogged filter restricts airflow, makes the system work harder than it needs to, and can reduce the warmth delivered to your rooms.

Locate your filter grille and remove it to inspect the filter inside. If it is visibly coated in dust and debris, it needs cleaning or replacing according to the manufacturer’s instructions. Many filters can be vacuumed gently or washed according to the manufacturer's instructions. Check your owner's manual for the correct method and replacement specifications for your model.

Not all gas heater types have user-accessible filters. Wall furnaces and some space heaters have different maintenance arrangements. If you are unsure whether your system has a filter or how to access it, consult your owner's manual or contact a licensed gasfitter. For an overview of the types of gas heating systems available in Australian homes, see AGN's gas heating buyer's guide.

Testing Your Heater Before Cold Weather Arrives

heater control

Turn your gas heater on for 10 to 15 minutes on a mild day before you need it in earnest. This gives you the opportunity to observe how it starts and runs without the pressure of needing heat urgently.

When you first switch the heater on after a long period of inactivity, a brief dusty or musty smell is common as accumulated dust burns off the heat exchanger. This typically clears within a few minutes. If the smell is persistent, resembles gas, or is accompanied by other changes such as unusual noises or error codes, turn the heater off.

During the test run, note the following:

Does the heater ignite reliably on the first or second attempt?
Is the pilot light flame visible through the inspection window stable or is it constantly flickering and wavering colour?
Does the heater reach and maintain temperature without cutting out?
Are there any unusual sounds such as banging, rattling, or persistent clicking?
Are there any warning lights or error codes on the display?

If the answer to any of these is unsatisfactory, note what you observed and contact a licensed gasfitter before relying on the heater through winter.

IF YOU SMELL GAS AT ANY POINT

Turn off the heater and all other gas appliances immediately.
Do not operate any electrical switches, lights, or ignition sources.
Open windows and doors to ventilate the space.
Leave the property.
Call the 24-hour gas emergency line on 1800 427 532 from a safe distance outside. Do not re-enter until the situation has been assessed as safe.

When to book a professional gas heater service

While homeowners can carry out the checks above, a full gas heater service must be performed by a licensed gasfitter. This is not a DIY task. Gas appliance servicing involves inspecting and adjusting internal components, testing gas pressure, checking for leaks, and testing safety controls. These steps require a licensed professional with the appropriate qualifications and equipment.

Energy Safe Victoria recommends all gas heaters be serviced at least every two years by a qualified gasfitter. Most manufacturers will also specify a service interval in your appliance manual. If you are overdue for a service, or if your heater showed any concerns during the test run above, this is the time to book.

A professional gas heater service typically covers the following, though inclusions vary by provider, heater type, and condition:

Inspecting and cleaning the burner and combustion components
Checking gas pressure and supply connections
Testing the flue for correct operation and checking for blockages or spillage
Inspecting the heat exchanger for cracks or deterioration
Testing safety controls, thermostats, and ignition systems
Checking for gas leaks at connections and fittings
Testing for carbon monoxide spillage where applicable

When booking, ask the gasfitter what their standard service covers and whether there are any additional checks recommended for your specific heater type or age.

Heater repaired and inspected by a licensed gas fitter

Signs your gas heater may need repair or replacement

The heater does not ignite, or requires repeated attempts before starting
The flame appears yellow or orange rather than blue, which may indicate incomplete combustion and should be assessed by a licensed gasfitter
Unusual sounds during operation such as banging, rattling, loud popping, or persistent clicking
Unusual odours during normal operation, other than a brief dusty smell when first switched on
The heater runs but fails to heat the space adequately, or heats unevenly
Warning lights or error codes are displayed on the unit
Visible soot, staining, or unusual condensation around the heater or its flue

Find a licensed gasfitter

A professional gas heater service is a thorough inspection and maintenance check carried out by a licensed gasfitter. It is designed to assess how the heater is operating, identify any wear or developing faults, and confirm the appliance is safe and performing efficiently. This is not something a homeowner should attempt.

If your heater is older and experiencing recurring faults, a licensed gasfitter can also advise on whether repair or replacement is the more practical option. See our article on gas heater service: signs you need one and what it costs for a more detailed look at each of these warning signs.

FAQs about pre-winter gas heater servicing checklist

Energy Safe Victoria recommends servicing at least every two years by a qualified gasfitter. Most manufacturers specify a service interval in the appliance manual, and that guidance takes precedence for your specific model. A licensed gasfitter can advise on what is appropriate for your system based on its age and condition.

Gas heater servicing must be carried out by a licensed gasfitter. Homeowners can safely perform basic maintenance such as cleaning or replacing filters and checking that external vents are clear of obstructions. Any work involving gas supply connections, the burner, the heat exchanger, flue components, or internal safety controls is restricted to licensed professionals by law in all Australian states and territories.

Service costs vary depending on the type of heater, your location, the gasfitter, and whether any repairs or parts are needed. Ducted systems generally involve more work than a single space heater and may take longer. The most reliable way to understand what a service will cost for your specific situation is to contact two or three licensed gasfitters in your area and ask for a quote before the work begins.

A brief, mild dusty or musty smell when a gas heater is switched on after a long period of inactivity is common. It is typically caused by dust burning off internal components as the heater warms up and usually clears within a few minutes. If the smell is persistent, intensifies, resembles gas, or is accompanied by other symptoms such as unusual noises or error codes, turn the heater off immediately and contact a licensed gasfitter before using it again.

A few practical steps may help reduce what you spend on heating. Having your heater professionally serviced can help identify issues that may affect performance. Any impact on energy use or running costs will depend on the heater’s age, condition, settings, usage and the home itself. Using a programmable thermostat or timer can help avoid heating an empty home. Closing doors to rooms you are not using reduces the area the system has to heat. Draught-sealing gaps around doors and windows can also help retain warmth. For more on managing energy use over winter, see AGN's guide on how to avoid bill shock during winter and our 10 ways to reduce your gas bill.

References

Australian Government (energy.gov.au): Winter energy savings - energy.gov.au

Australian Government (energy.gov.au): Heating and cooling - filter and servicing guidance - energy.gov.au

Australian Government (YourHome): Heating and cooling - thermostat efficiency guidance - yourhome.gov.au

Victorian Building Authority: Building and Plumbing Commission

This article is general information only and does not take your specific circumstances into account. Costs, eligibility, and connection requirements can differ by state, property type and over time. For appliance selection, servicing and safety advice, speak with a licensed gasfitter and follow the manufacturer instructions.

All information provided in this article was correct at the time of publishing (June 2026)

Want to know more? Give us a call on 1300 001 001 or click here to learn more about our gas network and connection process, including current eligibility, fees and restrictions in your area.