Why is only some of the house getting warm?

In a ducted system that is usually the ductwork rather than the heater: a duct that has come off its outlet in the roof space, crushed flexible duct, or zone motors that have failed. It is worth describing which rooms are affected when you book, because it points the technician at the roof rather than the unit.

How dangerous is carbon monoxide from ducted gas heating?

It is the reason the spillage test exists as a standard part of servicing. A heat exchanger can crack and the heater will keep running and keep heating, while combustion products enter the air being circulated through the house. That is why 'it still works' is not evidence a gas heater is safe, and why the test result should be given to you in writing.

Who to hire for ducted heating that stopped

Short answer

For ducted gas, a licensed gasfitter with a gas appliance endorsement. For ducted reverse-cycle or a ducted heat pump, a heating and cooling technician with a refrigerant handling licence. Work out which you have first — the unit is in the roof or under the floor and the label on it answers the question.

Soon, not tonightIt will not usually get cheaper by waiting, and it is rarely worth an after-hours rate.

When it is someone else

Calling the wrong trade costs an attendance fee to be told so. These are the cases where this problem belongs to someone other than a heating and cooling business.

an electrician
the system is completely dead and the circuit has tripped.

What to do before anyone arrives

Find the unit and photograph the data plate. Gas or refrigerant is the first fork in the road.
Check the thermostat: batteries, setpoint, and whether it is in the right mode. A dead thermostat battery is a very common call-out.
Check the return air filter. Ducted systems have one and it is routinely never touched.
For gas: check other gas appliances work, and note any error code shown on the unit.
Say out loud whether anyone in the house has had unexplained headaches or nausea in the heating season. That changes the urgency.

What to ask when you book

Does the service include a carbon monoxide spillage test, and will I get the reading in writing?
Do you hold the gas appliance endorsement, or the refrigerant handling licence, whichever applies?
Are parts available for this unit, or is this the conversation about replacement?
Will you check the ductwork as well as the unit? Disconnected ducts in a roof heat the roof space.

What changes the price

No dollar figures here: this directory holds no price data and an invented range is worse than none. What follows is what makes one of these jobs cost more than the same job next door, which is the part you can actually use when comparing quotes.

Unit repair versus replacement, and parts availability for older heaters.
Duct condition — collapsed or disconnected ducts are a separate job and a common finding.
Access, especially for a unit in a roof space.
Whether the flue needs work.

What you can do yourself

Is this licensed work?

Gas ducted heating is gasfitting work with a separate appliance endorsement; refrigerant-based ducted systems require a refrigerant handling licence. Both involve licensed electrical connections.

There is no national register. Search the licence number with the regulator for the state the work is happening in.

NSWNSW Fair Tradingbuilders, electricians, plumbers and specialist trades
VICBuilding and Plumbing Commission, and Energy Safe Victoria for electricalbuilding practitioners and plumbers; electricians are Energy Safe Victoria
QLDQueensland Building and Construction Commission (QBCC)building and most trade contractor licences
WABuilding and Energybuilders, electricians, plumbers and gas fitters
SAConsumer and Business Servicesbuilding work contractors and supervisors
TASConsumer, Building and Occupational Services (CBOS)building and occupational licences
ACTAccess Canberraconstruction occupations licensing
NTNT Government building practitioner registrationbuilding practitioners and electrical workers

Licensing thresholds and certificate requirements differ by state and change with amending regulation, so this page describes the mechanism rather than quoting a figure. The regulator’s own page is the current answer.

Common questions

Who should I hire for ducted heating that stopped working: For ducted gas, a licensed gasfitter with a gas appliance endorsement. For ducted reverse-cycle or a ducted heat pump, a heating and cooling technician with a refrigerant handling licence. Work out which you have first — the unit is in the roof or under the floor and the label on it answers the question.
Why is only some of the house getting warm?: In a ducted system that is usually the ductwork rather than the heater: a duct that has come off its outlet in the roof space, crushed flexible duct, or zone motors that have failed. It is worth describing which rooms are affected when you book, because it points the technician at the roof rather than the unit.
How dangerous is carbon monoxide from ducted gas heating?: It is the reason the spillage test exists as a standard part of servicing. A heat exchanger can crack and the heater will keep running and keep heating, while combustion products enter the air being circulated through the house. That is why 'it still works' is not evidence a gas heater is safe, and why the test result should be given to you in writing.

Find a heating and cooling business near you

2,138 heating & cooling in this directory, ranked on published evidence rather than on advertising.

Who to hire for

General information about who does what, not advice about your specific job. Licensing, consumer law and council rules differ by state and change; the regulator for your state is the current source. More guides to hiring a tradesperson.