Install, service, repair and remove gas space heating appliances

Business Sectors (Suites): Downstream Domestic Gas Installation and Maintenance
Developed by: Energy & Utility Skills
Approved on: 01 Jan 2022


This standard is about working on gas space heating appliances in domestic settings.  Appliances can include fires and wall heaters and may involve working with some electricity systems. 

As well as servicing and repairing, this standard covers the work activities of installing and removing gas space heating appliances including when required for new installations or when exchanging, replacing or repositioning gas appliances.  It includes the disconnection, de-commissioning, testing and commissioning that is involved.  It can apply to any type of fuel gas or combinations of fuel gas including, but not restricted to, natural gas, LPG, blended or 100% hydrogen.

This standard should be used in conjunction with:
EUSDSG5 Prepare to work on gas systems or appliances in domestic settings; and
EUSDSG15 Carry out gas tightness testing and check system safety  in small settings

This standard is for gas engineers who work in domestic settings.

Performance criteria

You must be able to:

1. Make sure all required pre-work checks have been carried out prior to starting installation, service, repair or removal activities
2. Carry out all stages of the work in line with installation, maintenance or removal plans or activities
3. Carry out installation, service, repair, test and removal processes in accordance with manufacturers’ specification, industry standards, safety schemes and regulations
4. Carry out installation, service, repair, testing and removal in line with recognised industry practices, work standards, routines and sequences
5. Check that conditions within gas and electricity systems will permit safe de-commissioning and commissioning
6. Use designated safe isolation procedures and warning notices to prevent the unauthorised use of un-commissioned or de-commissioned gas appliances, gas systems, electrical systems and components 
7. Use the correct tools, test equipment and other equipment for each stage of the work being carried out
8. Assemble gas and electricity system components to meet requirements of plans
9. Minimise damage to customer property and building features throughout all stages of the work
10. Confirm position of new, replacement or repositioned appliances meet location, siting and clearances required by manufacturers’ instructions, industry standards’ specification and building regulations
11. Confirm ventilation for new, replacement or repositioned appliance installations meet industry standards,  manufacturers’ instructions and building regulations
12. Ensure existing systems are clean and free of debris
13. Fix and connect all relevant pipes and components to gas space heating appliances in line with plans
14. Confirm the operation of condensate disposal systems in line with manufacturers’ instructions
15. Use tightness testing and purging, safe isolation and electrical testing procedures to confirm the integrity of systems and appliances
16. Use industry standard checks and testing procedures to confirm the integrity of flues/chimney systems, condensate pipe and appliance flue seals
17. Check appliance operating pressure and gas rate meet industry standards and manufacturers’ requirements
18. Use industry standard visual checks and flue gas combustion analysis with approved test equipment to confirm combustion performance 
19. Check gas space heating appliances and systems function safely and operate in accordance with manufacturers’ instructions
20. Check electrical systems and components function safely and operate in accordance with manufacturers’ instructions
21. Complete and submit all relevant documentation and paperwork in line with industry standards and legislative requirements
22. Instruct property occupiers on the correct operation of appliances and systems and provide them with their copy of appliance literature
23. Resolve problems within own area of responsibility and competence in accordance with approved procedures 
24. Advise of any delays to the work, unresolved problems, unsafe situations and required remedial actions to those who require the information

Knowledge and Understanding

You need to know and understand:

1. Regulations and guidance governing health and safety in the workplace, environmental protection and the use of risk assessments including safe access, working at heights, those relating to substances hazardous to health and building regulations
2. Legislation covering your general responsibilities for your own safety and that of others
3. The limits of your own autonomy and responsibility
4. Gas industry unsafe situations procedures and how to isolate unsafe gas appliances, gas systems and components 
5. Potential hazards that could arise from all de-commissioning, installation, service, repair, removal and commissioning activities and checks to be carried out before work takes place
6. How to access and interpret normative documents, industry standards guidance documents, manufacturers’ instructions, industry standards, safety schemes and regulations including when it is appropriate to seek concessions to manufacturers instructions which cannot be fully met and how to do this
7. Required pre-work checks including operating pressures and volumes, Industry practices, work standards routines and sequences for installing, servicing, repairing, exchanging, repositioning, replacing, testing, connecting, removing, de-commissioning and recommissioning gas space heating appliances and associated systems and components 
8. Tests and checks to confirm the suitability of gas combustion performance including the use of approved flue gas analysers
9. Tests and checks to confirm the integrity, suitability, performance, operating pressure, gas rate and safe functioning of gas space heating appliances including the use of test equipment
10. Tests and checks to confirm the integrity, suitability and performance of flues/chimneys and ventilation systems
11. Procedures for checking gas space heating appliance performance including pressure, flow rate and temperatures 
12. How to measure and record installation and site details for prefabrication 
13. How to confirm that services and system requirements are adequate for gas system and components
14. Safe isolation methods, tests, and procedures for temporary and permanent de-commissioning of gas and electricity systems, components and appliances including use of temporary continuity bonds, non-contact voltage detectors, voltage indicators, proving units, multimeters
15. Measures to prevent un-commissioned and de-commissioned appliances or systems being brought into operation 
16. Positioning and fixing requirements for gas space heating appliances and associated systems and components 
17. Methods of working which protect building décor, customer property and existing systems and components
18. Safe processes and procedures for applying tightness testing and purging, safe isolation and electrical testing to appliances, gas systems and components to ensure safe functioning
19. How to safely collect and dispose of system contents that may be hazardous to health or the environment
20. The steps to take when problems arise with work activities 
21. Job management structures and methods of reporting and recording job progress or problems delaying progress
22. How to complete documentation and records and which statutory body to submit it to including building regulation self-certification
23. System and appliance handover and demonstration procedures 


Scope Performance

Scope Knowledge





Links To Other NOS

External Links

Version Number


Indicative Review Date

01 Jan 2025





Originating Organisation

Energy & Utility Skills

Original URN


Relevant Occupations

Domestic Gas Engineers

SOC Code



install, domestic, gas, space heating, installation, gas, energy, utility, utilities, maintain, maintenance, commission, decommission, replace, LPG, blended fuel, 100% hydrogen