Yes, an existing gas line may be extended or branched if a licensed gasfitter confirms that the full installation is sound, compliant and able to supply the combined appliance demand. This assessment is essential when replacing an electric cooktop with gas or adding any new gas appliance.
There is no standard gas line size for a gas cooktop. An appropriately licensed NSW gasfitter must calculate the required size from the cooktop’s maximum gas consumption in MJ/h, pipe length and material, available pressure, gas type and demand from other connected appliances.
What determines the pipe size?
The gasfitter assesses:
- Appliance demand: The cooktop’s data plate or manufacturer’s instructions state its maximum gas consumption and required inlet pressure.
- Pipework: Developed length, material, internal diameter, fittings and branches affect capacity and pressure loss.
- Other appliances: Shared pipe sections must carry the combined demand of the appliances they supply.
- Supply conditions: Natural gas and LPG have different characteristics and supply conditions, so their sizing requirements are not interchangeable.
The gasfitter uses the applicable pipe-sizing provisions of AS/NZS 5601.1, together with the appliance instructions and piping-system requirements. Cooktop width and burner count alone cannot determine the correct size.
Is 22 mm gas pipe required?
No. A 22 mm copper pipe may suit part of some installations, but it is not universally required or necessarily adequate. Its capacity depends on the pipe’s internal bore, length, available pressure, gas type and downstream load. Other pipe materials use different dimensions and capacity data.
How is an existing line checked?
A licensed gasfitter identifies the full pipe route and material, confirms all connected appliance loads, calculates demand on each pipe section and verifies that the required pressure is available under operating conditions. Visible pipe diameter alone is not enough.
After alteration and testing, ask the gasfitter which NSW gas compliance documentation applies to the completed work.
What affects the cost?
There is no reliable fixed price before inspection. The quote depends on the route and length of the extension, pipe material, appliance demand, property location, access, labour, current market conditions, testing requirements and whether further faults or supply limitations are found.
Do not size, alter, connect, test or commission gas pipework yourself. Gas work presents fire, explosion and carbon monoxide risks and requires an appropriately licensed gasfitter in NSW.
For a new branch or gas point, contact our licensed gas point installation team to assess, size, install and test the pipework before appliance connection.