Skip to content
LokalMatch

Ducted Heating Repair

Ducted Heating Repair near you

Ducted gas heating repair covers the faults that stop a central gas heater working properly: no heat at all, air that never gets warm, a unit that lights and then shuts down, weak airflow at the outlets, or noise and smells that were not there last winter. The heater unit itself usually sits out of sight in the roof space or under the floor, which is part of why these faults go unnoticed until a cold June morning.

Tell us about your furnace repair project and we’ll help you find local HVAC technicians who serve your area.

Free for homeowners · No obligation to hire

Need help urgently? Choose “Emergency” when you request quotes and we’ll look for pros who take urgent jobs.
This type of work often has to be done by a licensed or certified trade. Ask to see licences and proof of insurance before work starts.
On this page

Repairs on this equipment are not general handyman work. Servicing, repairing and testing a gas appliance is gasfitting, and the person doing it needs the right licence and, for domestic appliance servicing in Victoria, a gas servicing Type A endorsement on their licence card. Type A appliances are the everyday ones: cookers, space heaters, central heaters and water heaters.

There is also a safety dimension that a homeowner cannot assess from the hallway. Carbon monoxide is colourless and odourless, and Energy Safe Victoria warns that any gas heater can spill it, including central heating units, space heaters, wall furnaces and decorative log fires. A cracked heat exchanger in a ducted heater tucked into a roof space can leak combustion products into the air the house is breathing without anyone seeing a thing, which is why the safety test matters as much as the fix.

Signs your ducted gas heating needs a repair or a safety check

  • The system runs but the air from the outlets is barely warm, or the house never reaches the temperature set on the controller.
  • The heater lights, runs briefly and then shuts down, repeating the cycle instead of settling.
  • Airflow at the outlets is noticeably weaker than last winter, or some rooms get nothing while others are fine.
  • Banging, rattling, whistling or a rumble on ignition that the system did not make before.
  • A smell of burning dust that does not clear after the first few runs of the season, or any smell of gas at any time.
  • Sooty or yellow-brown staining around the heater, the flue or an outlet.
  • Anyone in the household gets headaches, nausea, dizziness or tiredness that eases when they leave the house, which Victorian health guidance lists among carbon monoxide symptoms.

Common ducted gas heater faults and what causes them

  • Ignition and flame failure: a faulty igniter, a dirty or failed flame sensor or a gas supply problem stops the burner establishing or holding a flame.
  • Overheating shutdowns: a blocked return air filter or collapsed ductwork starves the heat exchanger of airflow, so a safety switch trips the unit out.
  • Fan and motor faults: a failed capacitor, worn bearings or a seized blower motor shows up as noise, weak airflow or a unit that heats but does not distribute.
  • Thermostat and control faults: a failed wall controller, a wiring problem or a control board fault makes the system behave erratically or ignore the set temperature.
  • Duct and zone problems: disconnected duct in the roof space, crushed flexible duct or a stuck zone motor delivers heat to the roof cavity instead of the bedrooms.
  • Flue and spillage problems: a blocked, corroded or poorly terminated flue stops combustion products leaving the house safely.
  • Heat exchanger cracks: Energy Safe Victoria identifies carbon monoxide being drawn into a building from a cracked heat exchanger or damaged combustion chamber seals as a hazard in central heating units located outside, in a roof space or under a floor.

Gas smell or carbon monoxide symptoms: what to do straight away

Treat a suspected carbon monoxide problem as urgent, not as something to raise at the next service. Victorian health guidance is that if you suspect you may be affected by carbon monoxide from a gas appliance you should immediately turn it off, open doors and windows to ventilate the area, leave the property and seek medical advice immediately. In an emergency, call triple zero. Symptoms to take seriously include tiredness, shortness of breath, headaches, dizziness, nausea, weakness, confusion and chest pain, and a strong warning sign is several people, or people and pets, becoming unwell at the same time or only when they are at home.

Energy Safe Victoria's advice for a heater you are worried about is blunt: do not use it until it has been checked by a qualified gasfitter. Turning the system off at the controller and leaving it off until it has been inspected costs you a cold week; the alternative is not a risk worth carrying.

If you can smell gas rather than suspect carbon monoxide, do not operate electrical switches or appliances in the area, ventilate the space, turn off the gas supply if it is safe to reach, and get everyone out before calling for help from outside the building.

What a gasfitter does on a ducted heating service or repair call

A proper visit is a safety inspection with a repair attached, not just a parts swap. Energy Safe Victoria's guidance for a gas safety check is that the gasfitter carries out a gas fitting line test to check for leaks, inspects the appliance installation to identify safety-critical non-compliances, checks for spillage of combustion products, and services the appliances. In Victoria that service work is reported to the plumbing regulator through its online gas servicing portal.

The spillage test is the part homeowners most often have not heard of. The gasfitter runs the appliance and checks for combustion product spillage, including under negative pressure created by running exhaust fans and rangehoods, because Energy Safe Victoria notes that sealing buildings for energy efficiency combined with high-capacity extraction fans can adversely affect the safe operation of internal open-flue gas appliances and lead to carbon monoxide spillage. A heater that passes with everything off can still fail with the kitchen rangehood running.

Ask for the results in writing. A service record that lists the tests carried out, the readings taken and the parts replaced tells you far more than an invoice saying serviced, and it is the document you will want if the same fault returns or if you are a rental provider who must keep a record of the gas safety check.

Keeping a gas central heater safe between repairs

The single most important maintenance item is not something you do yourself: Energy Safe Victoria, Victorian health guidance and Sustainability Victoria all say gas heaters, including central heating units, should be serviced at least once every two years by a qualified gasfitter, and in Victoria that gasfitter should be endorsed to carry out Type A gas appliance service work. Put it in the calendar for autumn rather than waiting for a fault.

  • Keep the return air grille clear and clean or replace the filter as the manual specifies, since restricted airflow is behind a large share of overheating shutdowns.
  • Do not run the heater and a kitchen rangehood or bathroom exhaust fan at the same time if you have an open-flued appliance, because the fans can pull combustion products back into the room.
  • Keep furniture, curtains and stored boxes away from outlets and from the unit itself.
  • Never use an oven or a cooktop to heat a room, which Energy Safe Victoria warns against explicitly.
  • Turn radiant gas heaters off when you leave the house or go to sleep rather than leaving gas heating running overnight.
  • Note anything that changed, such as a new noise, a new smell or a new draught, and tell the gasfitter at the next service instead of waiting to see whether it gets worse.

Repairing an old ducted gas heater or replacing the system

Some repairs are clearly worth doing. An igniter, a flame sensor, a capacitor, a fan motor or a wall controller on an otherwise sound and reasonably efficient system is a straightforward job, and the system goes back to working as it did.

Other findings change the conversation. A cracked heat exchanger is not a patch-and-hope repair, and on an older unit the cost of the part and the labour to reach it in a roof space often approaches the cost of a new system. Repeated faults in a single season, obsolete parts, poor efficiency and ductwork that has degraded across the whole house all point the same way.

If replacement is on the table, compare a like-for-like gas replacement against an efficient reverse cycle system rather than assuming the former. Sustainability Victoria's position is that electric reverse cycle is the lowest cost heating option for most Victorians, Victorian Energy Upgrades offers its largest heating discounts to households replacing a ducted gas heater with an approved high-efficiency reverse cycle system, and a reverse cycle system also cools in summer. A failed heater in June is a bad moment to make that decision, which is an argument for making it in autumn.

Who is legally allowed to repair a gas heater in Australia

Repair work on a gas appliance is licensed work everywhere in Australia, and Energy Safe Victoria puts the reason bluntly: gas and electricity are inherently dangerous, and it is illegal and potentially fatal for unlicensed and unqualified people to undertake any gasfitting or electrical work. There is no homeowner exception for opening up a gas heater, and online videos showing otherwise are not written for Australian rules.

In Victoria, licensing and registration for plumbers and gasfitters is administered by the plumbing regulator, practitioners carry a photo identification card showing the classes of work they may perform, and domestic appliance servicing requires the gas servicing Type A accreditation on that card. Ask to see it and read the back. Queensland works differently again: you need a licence or authorisation before you do any gas work at all, regardless of whether the work is residential, commercial or industrial, and gas work is defined broadly enough to include servicing, testing and certifying a gas system.

The practical rule for a homeowner is simple. Filters, grilles and controller settings are yours. Anything behind the panel, anything involving the burner, the flue or the gas line, and anything requiring a carbon monoxide test belongs to a licensed gasfitter with the right endorsement.

Ducted Heating Repair: frequently asked questions

How often should a ducted gas heater be serviced in Australia?

At least once every two years by a qualified gasfitter, which is the consistent advice from Energy Safe Victoria, Victorian health guidance and Sustainability Victoria, and the interval applies to central heating units as much as to space heaters. In Victoria the gasfitter should be endorsed to carry out Type A gas appliance service work, and the service should include a test for carbon monoxide spillage.

Can carbon monoxide really come from a ducted heater in the roof space?

Yes. Energy Safe Victoria specifically identifies carbon monoxide being drawn into a building from a cracked heat exchanger or damaged combustion chamber seals in central heating units located outside a building, in a roof space or under a floor, and notes that this spillage can go unnoticed. Because carbon monoxide is colourless and odourless, the only reliable check is a gasfitter testing for spillage with the right instrument.

Why does my heater shut down after running for a few minutes?

Short cycling like that is often a safety device doing its job. Restricted airflow from a blocked filter, a closed-off return air path or collapsed ductwork lets the heat exchanger get too hot, so the unit trips out. Flame sensing faults produce a similar pattern. Check the filter and make sure the return air grille is clear, and if it continues, book a gasfitter rather than resetting it repeatedly.

Is it safe to keep using the heater while I wait for a repair?

If anyone has symptoms that could be carbon monoxide, or you can smell gas, no. Turn the system off and leave it off, ventilate the house, and seek medical advice if people feel unwell. Energy Safe Victoria's advice for a heater you are concerned about is not to use it until a qualified gasfitter has checked it. For a purely mechanical complaint such as a noisy fan, using it briefly while you wait is a judgement call, but tell the gasfitter what you have observed.

Do I need to keep records of gas heater servicing if I rent the property out?

In Victoria, yes. Rental providers must keep a record of a gas safety check, gas safety checks are on a two-yearly cycle, and the gasfitter reports service work to the plumbing regulator through its online gas servicing portal. If you own a rental in another state, confirm the equivalent obligation with that state's regulator, because the requirements are not uniform across Australia.

How does LokalMatch work when my heating breaks down?

You describe the fault once, including your postcode, the type of system and whether anyone is unwell or you can smell gas, and heating businesses working in your area get in touch with you directly. Those businesses pay LokalMatch for the requests they receive. LokalMatch does not carry out repairs, does not set prices or quote on anyone's behalf, and does not vet, rank or recommend any business. If you suspect carbon monoxide or a gas leak, act on the safety advice first and post the job afterwards.

Sources

  1. Energy Safe Victoria: Heating your home with gas
  2. Energy Safe Victoria: GIS 38 Testing for negative pressure and carbon monoxide spillage
  3. Energy Safe Victoria: Gas safety checklist FAQs
  4. Energy Safe Victoria: Is your gas heater safe?
  5. Victorian Department of Health: Carbon monoxide poisoning in the home
  6. Better Health Channel: Gas heating health and safety issues
  7. Energy Safe Victoria: Using gas safely
  8. Business Queensland: Gas work licences and authorisations

Written by the LokalMatch editorial team. Last reviewed 14 September 2026. How we write and check our guides

What affects the cost of furnace repair

Prices depend on the details of your project. We only publish price ranges when they’re backed by real LokalMatch quote data or reliable sources. Until then, here’s what usually changes the price:

  • Type of system and fuel source
  • Size and efficiency of the equipment
  • Condition of the existing ductwork and venting
  • Electrical or gas line changes
  • Access to the furnace room, attic or outdoor unit location
  • Removal and disposal of the old equipment
  • Emergency or after-hours service

How to compare HVAC technicians before you hire

  • Hire a technician who is licensed for heating, cooling and gas work in your area.
  • For a new system, ask for a load calculation for your home rather than a size based on the old unit.
  • Get written quotes that list the equipment, ductwork changes, removal of the old unit and any electrical work.
  • Ask how they handle service calls and repairs after installation, including in the middle of winter.
  • Compare the full scope of each quote, not only the equipment on it.

Questions to ask HVAC technicians before you hire

  • Are you licensed for this type of heating, cooling or gas work in my area?
  • How did you decide what size of system my home needs?
  • Does this installation need a permit, and will you take care of it?
  • What does the manufacturer's warranty cover, and what does your labour warranty cover?
  • Will you need to change the ductwork, venting or electrical to make this work?
  • Do you offer maintenance plans, and what do they include?
  • How quickly can you respond if the system stops working?

When to call a pro for furnace repair

  • If you smell gas, leave the home and call your gas utility's emergency line from outside.
  • If a carbon monoxide alarm goes off, get everyone outside and call emergency services.
  • No heat in cold weather, or a furnace that keeps shutting off
  • Unusual noises, burning smells or a big jump in energy use

Furnace repair permits and local rules

Some furnace repair work needs a permit or has to meet local bylaws. Rules vary by municipality, so ask your pro whether a permit is needed and who will apply for it — and check with your city or town if you’re unsure.

Permits and licensing

Seasonal maintenance

This job is part of our home maintenance checklists for:

Ready to get furnace repair quotes?

Tell us about your furnace repair project.

Do you offer furnace repair services?

Join LokalMatch to get matched with homeowners in the areas you serve.