NSW Gasfitting cheat sheet

In NSW, gasfitting work must be carried out by, or under the direct supervision of, a holder of a current qualified supervisor certificate issued by NSW Fair Trading for the relevant gasfitting category.

Notifiable gas work must be certified and reported to the relevant network operator or authority within the prescribed timeframe; the compliance certificate must be issued to the consumer on completion.

AS/NZS 5601.1 governs gas installations downstream of the outlet of the gas supply point; AS/NZS 5601.2 governs LP Gas installations in caravans, boats and mobile homes.

Type A appliances are certified under the Gas Appliance Certification Scheme (Australia); an uncertified appliance must not be installed or supplied.

Work on consumer piping that connects to a network must comply with the distributor's connection requirements in addition to AS/NZS 5601.1.

A licensed gasfitter must hold appropriate insurance and must not perform work outside the scope of the licence class held (e.g. natural gas vs LP Gas endorsements).

Records of compliance certificates, test results and appliance commissioning data must be retained and produced on request by the regulator.

Variations from a deemed-to-satisfy standard require documented alternative solutions supported by a competent person's certification.

Natural gas in NSW is predominantly methane (approx. 90%+) with a heating value near 38-39 MJ/m3 and a relative density around 0.6 (lighter than air).

LP Gas (propane) has a heating value near 93-95 MJ/m3, relative density around 1.5-1.6 (heavier than air), and accumulates at low points.

Stoichiometric combustion of methane: CH4 + 2O2 -> CO2 + 2H2O; propane: C3H8 + 5O2 -> 3CO2 + 4H2O.

Complete combustion requires adequate primary and secondary air; insufficient oxygen produces carbon monoxide (CO), a toxic gas with no odour.

Flame appearance indicates combustion quality: a sharp blue flame with slight inner cone indicates correct primary aeration; yellow tipping or lifting indicates incorrect air/gas ratio.

Ventilation requirements for an appliance depend on its type (flued/unflued), input rating and the room volume; AS/NZS 5601.1 contains the ventilation tables.

The lower explosive limit (LEL) for methane is approx. 5% and for propane approx. 2.1% by volume in air; the upper explosive limits are approx. 15% and 9.5% respectively.

Gas leak detection should use a calibrated combustible gas detector or soap solution; electronic detectors must be zeroed in fresh air before use.

Consumer piping must be sized so that pressure drop from the meter/regulator to the appliance does not exceed the allowable value in AS/NZS 5601.1 tables for the pipe material and gas type.

Copper pipe must not be used to convey gas containing more than a specified level of hydrogen sulphide; in NSW natural gas reticulation, copper is generally acceptable but must comply with the standard's material clauses.

All buried metallic pipe must have corrosion protection and be laid with adequate cover; PE pipe is used for buried LP Gas and natural gas mains and services.

Appliance clearances from combustible surfaces, flue terminal clearances from windows, doors and air intakes must comply with the manufacturer's instructions and AS/NZS 5601.1.

Flexible connections must be certified, of the correct length, not concealed in walls or ceilings, and must not pass through floors or partitions.

A manual shut-off valve must be installed upstream of each appliance and be accessible.

Flue installations must be continuous, adequately supported, terminate in accordance with clearance tables, and be fitted with a draught diverter where required by the appliance.

Appliances installed in enclosed spaces must have combustion air and, where required, ventilation openings sized to the appliance input and room volume.

Pressure test consumer piping with air or inert gas at the test pressure and duration specified in AS/NZS 5601.1 for the pipe volume and material; no drop in pressure indicates a sound installation.

Purging of pipework must be performed to remove air before introducing gas; purging to atmosphere must be done in a well-ventilated area away from ignition sources.

Operating pressure at the appliance inlet must be checked against the manufacturer's specified range with the appliance operating at full rate.

Gas rate can be verified by meter dial timing: gas rate (MJ/h) = (meter reading in m3 x heating value in MJ/m3) / time in hours.

Combustion analysis using a flue gas analyser measures CO, CO2, O2 and calculates CO/CO2 ratio; a ratio above the appliance manufacturer's limit indicates incomplete combustion requiring service.

Common faults: flame lift (excess primary air or high pressure), yellow flame (insufficient primary air or blocked burner ports), pilot outage (dirty orifice or thermocouple failure).

Thermocouple and flame rectification devices are safety controls; a flame failure device must shut off gas within the specified time on flame loss.

Commissioning records must include test pressures, gas rates, combustion readings and appliance settings, and be provided to the consumer.

Carbon monoxide is a colourless, odourless gas; unflued appliances in poorly ventilated spaces are a primary cause of CO poisoning in domestic settings.

A gas leak must be isolated at the meter or cylinder, the area ventilated, ignition sources eliminated and the network operator or emergency service notified.

LP Gas cylinders must be stored upright, secured, away from ignition sources and heat, with quantities in domestic storage limited by the relevant dangerous goods requirements.

Consumer protection obligations include providing a compliance certificate, clear operating instructions, warranty information and advising of any safety defects found.

Refrigerant and greenhouse gas reporting obligations apply to certain gases; venting of greenhouse gases to atmosphere is prohibited under environmental protection legislation.

Spillage and flue integrity testing must be performed after service or installation of open-flued appliances to confirm no products of combustion enter the space.

Emergency shutdown procedures, including isolation valves and appliance labelling, must be explained to the consumer on completion of work.

Asbestos and other hazardous materials may be encountered in older installations; work practices must comply with WHS legislation and safe work method statements.

Every installation must have a documented commissioning record, compliance certificate and as-installed drawing or schematic showing pipe sizes and appliance locations.

Defect classification: an immediate threat to life requires isolation and notification; a non-compliance not posing immediate risk requires rectification and re-inspection.

Testing instruments (manometers, combustion analysers, leak detectors) must be calibrated and within their calibration interval at time of use.

Pipe sizing calculations must account for diversity of appliance use where the standard permits, and for the pressure at the meter under maximum demand.

Appliance data plates must be checked for gas type, input rating and certification before installation; mismatched appliances must not be connected.

Work on existing installations requires assessment of the existing pipework capacity before adding load; undersized existing piping must be upgraded or the new load refused.

Records of gas work must be retained for the period specified by the regulator and made available for audit or investigation.

Consumer protection: the gasfitter must disclose all defects found, provide a written quote before additional work, and not perform unauthorised work.

Environmental: leakage of natural gas (methane) is a greenhouse gas emission; leaks must be repaired promptly and reported where required.

Waste gas, purged gas and used cylinders must be disposed of in accordance with environmental protection and dangerous goods requirements.

Safety signage and appliance labelling must identify gas type, isolation points and emergency contact information.

Incident reporting: serious gas incidents (fire, explosion, CO exposure) must be reported to the regulator and network operator as required.

Personal protective equipment, including gas detection, must be used when entering confined spaces or excavating near gas mains.

Excavation near gas mains requires dial-before-you-dig notification and hand excavation within the specified clearance of the pipe.

The qualified supervisor certificate holder is responsible for all gas work performed under their supervision, including work by apprentices and trades assistants.

Licence classes in NSW include gasfitting (natural gas), LP Gas, and medical gas; work must be within the scope of the class held.

Continuing professional development and licence renewal are conditions of holding a NSW gasfitting licence.

Advertising and signage must not misrepresent the scope of licensed work or imply certification not held.

The regulator may audit gas work and require production of compliance certificates, test records and commissioning data.

Unlicensed gas work is an offence and may result in infringement notices, prosecution and invalidation of insurance.

A gasfitter must not certify work they did not perform or supervise; false certification is a serious breach of licensing obligations.

Primary air is mixed with gas before the burner port; secondary air is drawn from the surrounding space to complete combustion at the flame.

The aeration factor for natural gas burners is typically around 40-50% primary air; LP Gas burners use a different injector size and aeration setting.

Incomplete combustion produces CO; symptoms include yellow flames, sooting, condensation and CO alarms activating.

Flue draught must be verified; a blocked or reversed flue causes spillage of combustion products into the occupied space.

Open-flued appliances require a permanent ventilation opening; the size depends on appliance input and whether the space is internal or external.

Gas appliance input ratings are stated at standard conditions; derating may be required at altitude due to reduced oxygen density.

A flame failure device must be tested on commissioning and at each service to confirm shut-off within the specified time.

Pipe material selection: copper for above-ground natural gas, PE for buried services, stainless steel corrugated for certain applications; material must be compatible with the gas.

Jointing methods: brazed copper joints must use silver solder with appropriate flux and be purged of flux residue; compression fittings must be accessible.

Support spacing for consumer piping must comply with AS/NZS 5601.1 tables for the pipe size and material.

Pressure testing: test pressure and duration depend on pipe volume; larger volumes require longer test times to detect small leaks.

Purging volume is approximately the internal volume of the pipework; purge to a safe location and verify gas at the appliance before ignition.

Pipework must be protected from physical damage, corrosion, and thermal movement; expansion loops may be required for long runs.

Identification: gas piping must be labelled with the gas type and flow direction at intervals and at penetrations.

Flue terminal clearances from openable windows, doors, air intakes and adjacent buildings are specified in AS/NZS 5601.1 tables and must be measured and recorded.

A flue must not terminate in a roof space, wall cavity or under a floor; it must discharge to external air.

Combustible surface clearances for appliances and flues are specified by the manufacturer and by the standard; the greater applies.

Appliances in bedrooms, bathrooms and other special spaces have restricted installation requirements due to ventilation and CO risk.

Seismic and wind loading: flues and appliance supports must resist wind and, where required, seismic forces.

Condensate from high-efficiency appliances must be drained to an appropriate discharge point.

Commissioning includes verifying flue integrity, draught, spillage and combustion readings before handover.

Systematic fault finding: verify gas supply pressure, then appliance inlet pressure, then gas rate, then combustion, then controls.

A manometer or digital pressure gauge is used to measure supply and operating pressures; readings must be compared to the manufacturer's specification.

Gas rate verification by meter timing confirms the appliance is receiving the correct energy input; low rate indicates undersized piping or a blocked regulator.

Combustion analyser readings (CO, CO2, O2, CO/CO2 ratio) must be recorded and compared to the manufacturer's limits.

Handover must include operating instructions, maintenance schedule, warranty details and emergency contact information.

Any safety defect identified during commissioning must be rectified or the appliance isolated and the consumer advised in writing.

Documentation of tests, readings and corrective actions forms the commissioning record retained by the gasfitter and provided to the consumer.

On detecting a gas leak: eliminate ignition sources, ventilate, isolate at the meter or cylinder, evacuate if necessary and notify the network operator or emergency services.

LP Gas is heavier than air and accumulates in low points such as pits, cellars and drains; approach low areas with a gas detector.

Natural gas is lighter than air and accumulates at high points and in roof spaces; ventilate at high level.

CO alarms should be installed in accordance with the manufacturer's instructions and AS/NZS 60335 requirements, near sleeping areas.

Environmental obligations: prevent release of refrigerant and greenhouse gases; recover and dispose of gases in accordance with legislation.

Spill response: absorbents and containment for liquid petroleum products; do not wash spills to drains.

Emergency plans and contact numbers must be available on site and explained to the consumer at handover.

Compliance certificates must be issued for notifiable gas work and a copy provided to the consumer and the network operator as required.

Certification must accurately describe the work performed, the gas type, appliance details and test results.

The regulator may conduct audits and require production of records; failure to produce records is a breach of licensing obligations.

Work must comply with AS/NZS 5601.1 (and 5601.2 for LP Gas in mobile installations) and with the relevant network operator's requirements.

Non-compliance may result in rectification orders, penalties, suspension or cancellation of the licence.

Insurance and public liability cover must be maintained as a condition of licensed practice.

Continuing education and staying current with amendments to standards and regulations is a condition of licence renewal.

Heating values: natural gas approx. 38-39 MJ/m3; propane approx. 93-95 MJ/m3; butane approx. 118-120 MJ/m3.

Relative densities: methane approx. 0.55-0.6; propane approx. 1.5-1.6; butane approx. 2.0-2.1 (air = 1).

Complete combustion of methane requires 2 volumes of oxygen per volume of methane; propane requires 5 volumes of oxygen per volume of propane.

Air contains approx. 21% oxygen; stoichiometric air requirement for methane is approx. 9.5 volumes of air per volume of gas.

CO is produced when oxygen is insufficient; CO binds to haemoglobin approx. 200-250 times more strongly than oxygen.

Ventilation openings must be permanently open, sized per AS/NZS 5601.1 tables, and not obstructed by screens finer than specified.

Gas detectors must be calibrated and bump-tested before use; LEL alarms typically trigger at 10-20% LEL.

Consumer piping must be installed so it can be tested and purged; isolation valves must be accessible and labelled.

Copper pipe must be annealed or hard drawn as appropriate; bends must not kink or reduce the bore.

Pipe penetrations through walls and floors must be sleeved and sealed to prevent gas migration.

Appliances must be installed level and secured; flue connections must be sealed and continuous.

Flexible connectors must not be used to connect appliances in inaccessible locations or where they could be damaged.

Gas piping must not be used as an earthing conductor or support for other services.

Installation must allow for maintenance access to burners, controls and flue components.

Pressure test with air or nitrogen at the specified pressure; a stable reading over the test duration confirms integrity.

Purging must be done to a safe location; verify gas at the appliance before attempting ignition.

Operating pressure must be measured at the appliance inlet with the appliance running at full rate.

Gas rate verification by meter timing: rate (MJ/h) = volume (m3) x heating value (MJ/m3) / time (h).

Combustion analysis: CO/CO2 ratio above manufacturer's limit indicates incomplete combustion; investigate air supply, burner condition and gas pressure.

Flame failure device testing: extinguish flame and confirm gas shut-off within the specified time.

Record all readings and corrective actions in the commissioning record.

Consumer protection: provide written quotes, disclose defects, do not perform unauthorised work, and provide compliance certificates.

CO safety: unflued appliances must not be installed in bedrooms or bathrooms; CO alarms recommended in sleeping areas.

Gas leak response: isolate, ventilate, eliminate ignition sources, notify network operator or emergency services.

LP Gas storage limits apply to domestic premises; cylinders must be upright, secured and away from ignition sources.

Environmental: prevent refrigerant and greenhouse gas release; recover gases; dispose of waste per legislation.

Excavation near gas mains requires notification and hand excavation within specified clearance.

Incident reporting obligations apply to fires, explosions and CO exposure incidents.

NSW gasfitting licences are issued by NSW Fair Trading; qualified supervisor certificate holders are responsible for work performed under their supervision.

Licence classes cover natural gas, LP Gas and medical gas; work must be within the scope of the class held.

Continuing professional development and licence renewal are conditions of holding a licence.

Compliance certificates must be issued for notifiable work and copies provided to the consumer and network operator as required.

The regulator may audit work and require production of records; failure to produce records is a breach.

Unlicensed gas work is an offence and may invalidate insurance.

False certification is a serious breach of licensing obligations.

Primary air is mixed with gas before the burner port; secondary air completes combustion at the flame.

Aeration settings differ between natural gas and LP Gas; injector sizes must match the gas type.

Incomplete combustion produces CO; symptoms include yellow flames, sooting, condensation and CO alarm activation.

Flue draught must be verified; a blocked or reversed flue causes spillage of combustion products.

Open-flued appliances require permanent ventilation sized per AS/NZS 5601.1 tables.

Appliance input ratings are stated at standard conditions; derating may be required at altitude.

Flame failure devices must be tested on commissioning and at each service.

Copper is used above ground for natural gas; PE for buried services; stainless steel corrugated for certain applications.

Brazed copper joints must use silver solder with appropriate flux and be purged of flux residue.

Compression fittings must be accessible and not concealed.

Support spacing must comply with AS/NZS 5601.1 tables for pipe size and material.

Pressure test pressure and duration depend on pipe volume; larger volumes require longer test times.

Purging volume approximates the internal pipe volume; purge to a safe location.

Pipework must be protected from damage, corrosion and thermal movement; expansion loops may be required.

Flue terminal clearances from windows, doors, air intakes and adjacent buildings are specified in AS/NZS 5601.1 tables.

A flue must not terminate in a roof space, wall cavity or under a floor; it must discharge to external air.

Combustible surface clearances for appliances and flues are specified by the manufacturer and the standard; the greater applies.

Appliances in bedrooms and bathrooms have restricted installation requirements due to CO risk.

Flues and appliance supports must resist wind and, where required, seismic forces.

Condensate from high-efficiency appliances must be drained to an appropriate discharge point.

Commissioning includes verifying flue integrity, draught, spillage and combustion readings.

Systematic fault finding: verify gas supply pressure, appliance inlet pressure, gas rate, combustion, then controls.

A manometer or digital gauge measures supply and operating pressures; compare to manufacturer's specification.

Gas rate verification by meter timing confirms correct energy input; low rate indicates undersized piping or blocked regulator.

Combustion analyser readings must be recorded and compared to manufacturer's limits.

Handover must include operating instructions, maintenance schedule, warranty details and emergency contact information.

Safety defects must be rectified or the appliance isolated and the consumer advised in writing.

Documentation of tests, readings and corrective actions forms the commissioning record.

On detecting a gas leak: eliminate ignition sources, ventilate, isolate at the meter or cylinder, evacuate if necessary and notify the network operator or emergency services.

LP Gas is heavier than air and accumulates in low points; approach low areas with a gas detector.

Natural gas is lighter than air and accumulates at high points and in roof spaces; ventilate at high level.

CO alarms should be installed near sleeping areas in accordance with the manufacturer's instructions.

Environmental obligations: prevent release of refrigerant and greenhouse gases; recover and dispose of gases per legislation.

Spill response: use absorbents and containment; do not wash spills to drains.

Emergency plans and contact numbers must be available on site and explained to the consumer.

Compliance certificates must be issued for notifiable gas work and a copy provided to the consumer and network operator as required.

Certification must accurately describe the work performed, gas type, appliance details and test results.

The regulator may conduct audits and require production of records; failure to produce records is a breach.

Work must comply with AS/NZS 5601.1 and 5601.2 and the network operator's requirements.

Non-compliance may result in rectification orders, penalties, suspension or cancellation of the licence.

Insurance and public liability cover must be maintained as a condition of licensed practice.

Staying current with amendments to standards and regulations is a condition of licence renewal.

Heating values: natural gas approx. 38-39 MJ/m3; propane approx. 93-95 MJ/m3; butane approx. 118-120 MJ/m3.

Relative densities: methane approx. 0.55-0.6; propane approx. 1.5-1.6; butane approx. 2.0-2.1 (air = 1).

Complete combustion of methane requires 2 volumes of oxygen per volume of methane; propane requires 5 volumes of oxygen per volume of propane.

Air contains approx. 21% oxygen; stoichiometric air requirement for methane is approx. 9.5 volumes of air per volume of gas.

CO is produced when oxygen is insufficient; CO binds to haemoglobin approx. 200-250 times more strongly than oxygen.

Ventilation openings must be permanently open, sized per AS/NZS 5601.1 tables, and not obstructed by screens finer than specified.

Gas detectors must be calibrated and bump-tested before use; LEL alarms typically trigger at 10-20% LEL.

Consumer piping must be installed so it can be tested and purged; isolation valves must be accessible and labelled.

Copper pipe must be annealed or hard drawn as appropriate; bends must not kink or reduce the bore.

Pipe penetrations through walls and floors must be sleeved and sealed to prevent gas migration.

Appliances must be installed level and secured; flue connections must be sealed and continuous.

Flexible connectors must not be used to connect appliances in inaccessible locations or where they could be damaged.

Gas piping must not be used as an earthing conductor or support for other services.

Installation must allow for maintenance access to burners, controls and flue components.

Pressure test with air or nitrogen at the specified pressure; a stable reading over the test duration confirms integrity.

Purging must be done to a safe location; verify gas at the appliance before attempting ignition.

Operating pressure must be measured at the appliance inlet with the appliance running at full rate.

Gas rate verification by meter timing: rate (MJ/h) = volume (m3) x heating value (MJ/m3) / time (h).

Combustion analysis: CO/CO2 ratio above manufacturer's limit indicates incomplete combustion; investigate air supply, burner condition and gas pressure.

Flame failure device testing: extinguish flame and confirm gas shut-off within the specified time.

Record all readings and corrective actions in the commissioning record.

Consumer protection: provide written quotes, disclose defects, do not perform unauthorised work, and provide compliance certificates.

CO safety: unflued appliances must not be installed in bedrooms or bathrooms; CO alarms recommended in sleeping areas.

Gas leak response: isolate, ventilate, eliminate ignition sources, notify network operator or emergency services.

LP Gas storage limits apply to domestic premises; cylinders must be upright, secured and away from ignition sources.

Environmental: prevent refrigerant and greenhouse gas release; recover gases; dispose of waste per legislation.

Excavation near gas mains requires notification and hand excavation within specified clearance.

Incident reporting obligations apply to fires, explosions and CO exposure incidents.

NSW gasfitting licences are issued by NSW Fair Trading; qualified supervisor certificate holders are responsible for work performed under their supervision.

Licence classes cover natural gas, LP Gas and medical gas; work must be within the scope of the class held.

Continuing professional development and licence renewal are conditions of holding a licence.

Compliance certificates must be issued for notifiable work and copies provided to the consumer and network operator as required.

The regulator may audit work and require production of records; failure to produce records is a breach.

Unlicensed gas work is an offence and may invalidate insurance.

False certification is a serious breach of licensing obligations.

Primary air is mixed with gas before the burner port; secondary air completes combustion at the flame.

Aeration settings differ between natural gas and LP Gas; injector sizes must match the gas type.

Incomplete combustion produces CO; symptoms include yellow flames, sooting, condensation and CO alarm activation.

Flue draught must be verified; a blocked or reversed flue causes spillage of combustion products.

Open-flued appliances require permanent ventilation sized per AS/NZS 5601.1 tables.

Appliance input ratings are stated at standard conditions; derating may be required at altitude.

Flame failure devices must be tested on commissioning and at each service.

Copper is used above ground for natural gas; PE for buried services; stainless steel corrugated for certain applications.

Brazed copper joints must use silver solder with appropriate flux and be purged of flux residue.

Compression fittings must be accessible and not concealed.

Support spacing must comply with AS/NZS 5601.1 tables for pipe size and material.

Pressure test pressure and duration depend on pipe volume; larger volumes require longer test times.

Purging volume approximates the internal pipe volume; purge to a safe location.

Pipework must be protected from damage, corrosion and thermal movement; expansion loops may be required.